Zeitschriften und Ausgaben

Volumen 26 (2019): Heft 4 (December 2019)

Volumen 26 (2019): Heft 3 (September 2019)

Volumen 26 (2019): Heft 2 (June 2019)

Volumen 26 (2019): Heft 1 (March 2019)

Volumen 25 (2018): Heft 4 (December 2018)

Volumen 25 (2018): Heft 3 (September 2018)

Volumen 25 (2018): Heft 2 (June 2018)

Volumen 25 (2018): Heft 1 (March 2018)

Volumen 24 (2017): Heft 4 (December 2017)

Volumen 24 (2017): Heft 3 (September 2017)

Volumen 24 (2017): Heft 2 (June 2017)

Volumen 24 (2017): Heft 1 (March 2017)

Zeitschriftendaten
Format
Zeitschrift
eISSN
2354-0133
Erstveröffentlichung
20 Dec 2019
Erscheinungsweise
4 Hefte pro Jahr
Sprachen
Englisch

Suche

Volumen 25 (2018): Heft 4 (December 2018)

Zeitschriftendaten
Format
Zeitschrift
eISSN
2354-0133
Erstveröffentlichung
20 Dec 2019
Erscheinungsweise
4 Hefte pro Jahr
Sprachen
Englisch

Suche

66 Artikel
Uneingeschränkter Zugang

Application of Drones in Protection of State Border

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 9 - 15

Zusammenfassung

Abstract

An unmanned aerial vehicle is a flying apparatus that does not require a crewmember on board to complete a task. Its piloting is done by means of indirect control. UAVs also have the ability to perform autonomous flight on a pre-programmed flight path. The purpose of the study was to use the unmanned aircraft “Fly Eye” by WB Electronic used by the Border Guard to patrol the state border in 103 TRA zone on the section of the Republic of Poland with the Kaliningrad District of the Russian Federation. The TRA zones constitute a specially designated area for the use of the Border Guard and the army, in order to carry out flights there beyond the scope of the pattern for training purposes and to patrol the state border. The article also contains information of the Border Guard formation and the characteristics of the unmanned aerial vehicle “FlyEye”. In order to ensure the safety of the UAV flight, the test was carried out in the TRA zone, which is used for special use for the Border Guard formation and the army.

Schlüsselwörter

  • Unmanned Aerial Vehicles
  • Flying Platform
  • Drone
  • Unmanned
  • UAV
  • Unmanned Aerial Vehicle
  • Fly Eye
  • Border Guard
  • Operator
Uneingeschränkter Zugang

The Role of Molecularly Ordered Structures in Energy Transport Enhancement During Combustion Process – A New Conception of a Reaction Mechanism of Fuel Components Oxidation

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 17 - 24

Zusammenfassung

Abstract

This article presents the results of investigations focused on the role of molecularly ordered structures (molecular clusters) on combustion process. The proposed new mechanism of the reactions initiation takes into account the role of molecular clusters in energy (heat and energy of electrons emitted by the surface of the walls of combustion chamber) conductivity regulation. Literature survey shows that molecular clusters created by aromatic hydrocarbons are responsible for particulate matter. The combustion process itself is not uniform in whole combustion chamber. Such diversity, caused mainly by heterogeneous thermal state of combustion chamber is recognized as significant reason to create various products of combustion including carbon oxides, carbon dioxides and nitrogen oxides. Jet fuel and its blends with n-butanol and biobutanol in concentration from 10 to 75 % (V/V) were subjected to laboratory tests. Such blends were also tested on the test rig with a miniature turbojet engine – MiniJETRig. Engine operating parameters and carbon oxide emission were measured. The relations between electrical conductivity and parameters of engine test (e.g. temperature in selected points in combustion chamber) were assessed. Engine tests were carried out according to specific profile of engine test, which models different engine operating modes. The results of experimental investigations, shown in the article, initially confirm the proposed mechanism of the oxidation reactions initiation during combustion process.

Schlüsselwörter

  • molecular clusters
  • turbojet engine
  • butanol
  • combustion process
  • carbon oxide emission
Uneingeschränkter Zugang

Database of Expert Diagnostic System in the Field of Turbine Blades Non-Destructive Testing

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 25 - 32

Zusammenfassung

Abstract

The article presents selected problems in the synthesis of the database of expert diagnostic system of gas turbine blades in the field of non-destructive testing. The source of data is optical methods and computed tomography methods. Optical tests can be carried out on the blades of the turbine built in the engine and after their disassembly. Optical tests provide diagnostic information in the form of an image of the blade surface. This makes it possible to identify damage based on changes in the attributes of the image of the blade surface. Computer tomography methods are applied on disassembled blades. Assessment of the technical condition of the blade is made on the basis of individual two-dimensional X-ray scans or on the basis of a three-dimensional image of the blade generated by the computer software from the set of X-ray scans taken during the full angle rotation. The computed tomography data set includes a small number of points on the timeline of operation; hence, the correlation of results with optical methods is difficult. Integration of diagnostic data from two or more sources into one expert system requires standardization of data. One possible approach is the use of multi-valued encoding of 2D and 3D image attributes. In this way a multi-valued diagnostic model of the blade is obtained, which can be processed by information theory methods to optimize the set of attributes.

Schlüsselwörter

  • gas turbine
  • blade
  • diagnostics
  • technical condition
  • expert system
  • database
Uneingeschränkter Zugang

Methods of Modern Aircraft Aeroelastic Analyses in the Institute of Aviation

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 33 - 42

Zusammenfassung

Abstract

The aeroelastic phenomena analysis methods used in the Institute of Aviation for aircraft, excluding helicopters, are presented in the article. In industrial practice, a typical approach to those analyses is a linear approach and flutter computation in the frequency domain based on normal modes, including rigid body modes and control system modes. They are determined by means of the finite element method (FEM) model of structure or a result of ground vibration test (GVT). In the GVT case, relatively great vibration amplitudes are applied for a good examination of a not truly linear structure. Instead or apart from the measure of generalized masses, a very theoretical model is used for mode shapes cross orthogonality inspection and improvement. The computed or measured normal mode sets are the basis for flutter analysis by means of several tools and methods, like MSC.Nastran and ZONA commercial software as well as our own low-cost software named JG2 for the flutter analysis of low speed aeroplanes and for a preliminary analyses of other aircraft. The differences between the methods lie in determining normal mode set, unsteady aerodynamic model, flutter equation formulation, time of analysis, costs, etc. Examples with results comparison obtained by means of distinguished methods are presented. Some works in the field of aeroelastic analysis with nonlinear unsteady aerodynamic in the time domain using Tau-code and ANSYS Fluent software were also performed. Aeroelastic properties of deformed structures, like a sailplane with deflected wings, can be also analysed. The simplest way of this analysis is the semi-linear approach in which the deflections modify the aircraft geometry for normal modes determination.

Schlüsselwörter

  • flutter
  • normal modes
  • ground vibration test
  • unsteady aerodynamic models
Uneingeschränkter Zugang

Effectiveness of the Active Pneumatic Suspension of the Operator’s Seat of the Mobile Machine in Depend of the Vibration Reduction Strategies

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 43 - 48

Zusammenfassung

Abstract

Low speeds of heavy mobile machines combined with large inertia result in the excitation of low frequency vibrations. Dissipation of vibration energy in the case of unsprung machines is performed only through tires, which slightly reduces the intensity of vibrations. Effective reduction of vibrations of mobile machines is possible only with active or semi-active methods. In unsprung mobile machines, on the way of propagation of vibrations between the source of vibrations and the protected object (machine operator), are vibroisolation systems located. These are most often controlled seat suspensions. In the case of the active suspensions, it is necessary to provide external energy, e.g. in the form of compressed air. The compressed air has the advantage that it is generally available in working machines as the working fluid and has its environmentally friendly properties (leaks do not contaminate the environment). This article is the result of the continuation of work on active methods of vibro-activity lowering in mobile machines, which resulted in, among others, elaboration of simulation model of the active operator’s seat suspension with controlled pneumatic actuator and its experimental identification. In particular, it was verifying the effectiveness of the adopted solution made the identification the friction model and thermodynamic phenomena in the controlled pneumatic cylinder. The aim of this work is parametric optimization of the suspension system and searching for the optimal control strategy. Experimental tests were carried out under conditions of harmonic excitations, coming from the electromechanical vibration exciter with controllable pitch and frequency. Data acquisition system and control circuit of the proportional directional control valve, supplying compressed air to the actuator were implemented using MATLAB-Simulink Real-Time software.

Schlüsselwörter

  • unsprung mobile machines
  • active vibration reduction
  • controlled suspension seats
  • pneumatic actuator
Uneingeschränkter Zugang

Experimental Study and Neural Network Modelling of Aerodynamic and Dynamic Characteristics of Flapping Wings Micro Aerial Vehicle

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 49 - 57

Zusammenfassung

Abstract

The article is close connected with building flying object, that fly like an insect (entomopter). Present work concerns on concept of aerodynamic model using artificial neural networks. Model is used in simulations of flight of entomopter. Aerodynamic model based on experimental data. Necessary data are taken from experiment performed in water tunnel on entomopter model. For this case dynamic test are required. Measurements are ducted during sinusoidal motion of whole model. Modelled object is dipterous. Each wing can perform various spherical motions (wing is rotated around point). The motion of the wing in this case was two-dimensional; it was rotated around two axis. As a model, specially trained neural network is used. For training are used data from measurement. Presented in this article approach is based on artificial neural networks. In this article, innovative concept of model, describing unsteady aerodynamics of entomopter was proposed. It was shown that it could be easily implemented as mathematical model. Unsteady effects related to many state variables can be easily captured. Model can be easily adopted to predict different states of flight by networks training on appropriate data. Test has to reproduce real conditions as close, as it is possible. In reality, it is challenging to design test that will reproduce similar motion.

Schlüsselwörter

  • entomopter
  • flapping wings aerodynamic neural network modelling
Uneingeschränkter Zugang

Processing of Long Lasting Signals of Torsional Vibrations Measured Using Incremental Encoders

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 59 - 65

Zusammenfassung

Abstract

The article describes processing method of a signal, coming from torsional deflections of an internal combustion piston engine’s crankshaft, registered using two optical encoders ETNP-10. Standard measurement and recording set ETNP-10 enables recording of Instantaneous Angular Speed values encompassing 10 revolutions of the crankshaft, what is equal to 5 cycles of four-stroke engine. That time duration is sufficient for analysis of changes of angular speed caused by, for example, malfunction of fuel injection valve, but is insufficient in case of observation characterized by low frequency changes with period of fluctuations, lower than 0.8 sec. Short time for recording makes impossible following of instantaneous angular speed deviations caused by magnitude modulation of engine’s load value. In the article is presented an algorithm written in MATLAB environment, which allows processing of the data recorded using the recorder DAS 1600 Sefram. The recorded this way signals have around 26 seconds' duration of engine work. Data acquired from two encoders mounted at opposite sides of the shaft, in form of square magnitude signals are transformed into instantaneous speed and subsequently to instantaneous angular shift, what is basis for torsions calculation. In the article is also presented method of elimination of systematic error due to assumed method of averaging. Finally, some examples of results of torsional deflection measurement and analysis are presented.

Schlüsselwörter

  • diagnostics
  • diesel engine
  • torsional vibrations
  • torque and angular speed
Uneingeschränkter Zugang

Tooling Development for Thermoplastic Composites Thermoforming Process Based on FEM Analysis – a Rib Case Study

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 67 - 74

Zusammenfassung

Abstract

Remarkable characteristics of high temperature thermoplastic (HTP) matrix used in composite materials reinforced with continuous fibres causes growing application in composite industry. Because of high processing temperature of some semi, crystalline matrix there is limited number of technologies that can be used for part manufacturing. Press forming is an example of technology that allows manufacturing high quality complex parts made of HTP reinforced fibres composite. In order to manufacture part with acceptable quality and mechanical properties, uniform pressure distribution during the process is required.

In this article, tooling design process focused on uniform pressure distribution for manufacturing of supporting rib was presented. In order to satisfy this requirement, the rubber stamp was proposed as a tool for manufacturing. Typical press forming process defects were identified and the requirements for rubber stamp were described. It was assumed that the forming process has to begin at one point on mould surface and sequentially continue in all directions. For stamp material, the two components additive silicone was selected. The hardness of the silicone was equal 40 Shore A. The rubber mechanical properties was determined through the additional tests and used for stamp designing. The tooling was designed using FEM software ABAQUS 6.12.

The sequence of stamp shape designing and optimization in order to meet the stamp requirements was presented. At the end the FEM rubber stamp designing recommendation were presented.

Schlüsselwörter

  • rubber thermoforming
  • rubber press forming
  • thermoplastic composite
Uneingeschränkter Zugang

The Influence of the Geometry of the Cutting Edge and Machining Parameters of Duplex Cast Steel After Turning

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 75 - 81

Zusammenfassung

Abstract

The development and research activity is connected to the production of newer and more functional products. Innovative processes are being developed and applied; services and projects are delivered. Products are work items that should be initially designed, then manufactured and finally sold and utilized. Examples of products may be airplanes, ships, cars, machine tools, gears, crankshafts, drive shaft, tubes as well as gasoline, electricity and gas, etc. The product has to meet the expectations of the future use. It is characterized by a set of functional features. In the case of machines and their capabilities and performance, for example, durability, reliability, resulting from the characteristics represented by the structural units forming the structure. The formation of the desired features of the surface layer in the technological process is an important problem due to the ability of the elements of kinematic pairs to fulfil the function as long as possible foreseen for them. The article presents results of experimental studies of turning cast steel grade GX2CrNiMoCuN25-6-3-3. The aim of the research was to determine the geometry of the cutting edge and the technological parameters of cutting that are conducive to obtaining the roughness in the field of very accurate machining. It can achieve the appropriate technological quality of the workpiece surface. After these experimental studies was determined that there is a reduction roughness using suitable inserts. Turning was made for the duplex cast steel. The technological parameters of machining process were used: feed rate f = 0.1-0.2 mm/rev, depth of cut ap = 0.5 mm, cutting speed vc = 50-100 m/min. Turning was made using universal lathe CDS 500x1000 equipped with CCMT carbide tipped inserts.

Schlüsselwörter

  • turning
  • finishing
  • forming surface layer
  • surface roughness reduction
  • duplex cast steel
Uneingeschränkter Zugang

Experimental Research of the Material Filtration Characteristics with Nanofibers Addition

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 83 - 94

Zusammenfassung

Abstract

Nanofiber properties and the possibilities of their application in industry, including car air intake filtration materials production for vehicle engines are discussed. The attention is paid to the standard filtration materials low efficiency in the range of dust grains below 5 μm. Filtration materials properties with nanofibers addition are presented. Filter paper test conditions and methodology at the station with particle counter were developed. Filtration efficiency characteristics, and accuracy studies as well as filtration materials pressure drop differing in structure were made: standard paper, and materials with nanofibers addition. These are commonly used filter materials for car air intake systems production. Filtration materials with nanofibers addition test results show significantly higher efficiency values, and efficiency for dust grains below 5 μm in comparison with standard filter paper. It was found that there are 16 μm dust grains in the airflow behind the cellulose insert, which may be the reason for the accelerated wear of the engine’s “piston-cylinder” association. Lower dust mass loading km values of filtration materials with nanofibers addition in relation to standard filter papers were observed.

Schlüsselwörter

  • engine
  • air filter
  • filtration materials
  • nanofiber filter media
  • filtration efficiency
  • filtration performance
  • pressure drop
  • dust mass loading
Uneingeschränkter Zugang

Electromobility and Hydrogenization of the Motor Transport in Poland Now and in the Future

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 95 - 101

Zusammenfassung

Abstract

The article analyses activities within the world, EU and Poland in aspect electromobility and hydrogenization now and in the future. Will be presented estimates cars park of global hybrid (HEV), hybrid plug-in (PHEV) and fully electric (BEV). Changes in production volumes and number of registered types of vehicles as abovementioned are presented in a breakdown into world.

The overall number of HEVs produced thus far is estimated at approx. 12.5 million and over 1.3 million in Europe. There are roughly 38 thousand HEVs registered in Poland. There were about 800.000 hybrid plug-in vehicles registered in the world in 2016. Of 3.2 million electric plug-in vehicles and BEVs used in the world in 2017 more than 1.2 million were used in China, approx. 750 thousand in the USA, 850 thousand in Europe, including c.a. 650 thousand in the EU countries.

Yet, electric plug-in vehicles (BEVs and PHEVs) globally accounted for just 0.3% of the worldwide fleet of passenger cars in 2017. The article also addresses the development of the electric vehicles market and the annual new vehicle registrations.

The existing situation in the field of hydrogenization motor transport in the world, in the EU and in Poland will also be analysed. This will be analysed in terms of the number of hydrogen vehicles and hydrogen refuelling stations.

Schlüsselwörter

  • road transport
  • hydrogenization
  • combustion engines
  • electromobility
  • environmental protection
Uneingeschränkter Zugang

Advantages of Using Hybrid Vehicles Based on Empirical Studies on the Chassis Dynamometer in the WLTC Test

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 103 - 109

Zusammenfassung

Abstract

Vehicles powered in alternative ways have an increasing share in the car market. Their use is becoming more and more justified considering the ever more stringent standards for the emission of harmful substances from the exhaust systems of internal combustion engines and the introduction of restrictions on vehicle traffic in city centres. The possibility of using in the propulsion systems only an electric motor or its simultaneous use with the internal combustion engine enables a significant reduction of emission of harmful exhaust gas pollutants. This applies in particular to urban areas, where there are numerous exceedances of acceptable air quality standards. This problem is most noticeable in larger cities in Poland, where there is a lot of traffic. It is therefore legitimate to promote alternative vehicles powered in alternative ways. Their dual power system gives the opportunity to significantly reduce the emission of harmful substances. Therefore, the article presents own research, carried out on a chassis dynamometer, using two passenger cars, one with a spark-ignition combustion engine and the second with a hybrid drive system containing a spark-ignition engine and an electric motor (system without the possibility of recharging batteries from external sources). Vehicles were characterized by similar mass and the same displacement volumes of internal combustion engines. The results of the tests made it possible to compare cars in terms of exhaust emissions. For testing purposes, a chassis dynamometer was used, on which the WLTC homologation cycle was repeatedly reproduced. This is a new driving cycle, which replaces the NEDC cycle used so far in the type approval procedure in the European Union.

Schlüsselwörter

  • road transport
  • combustion engines
  • hybrid powertrains
  • air pollution
  • exhausts emissions
Uneingeschränkter Zugang

Selected Problems to Support Decision Making in a Simulation Environment

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 111 - 117

Zusammenfassung

Abstract

The article is devoted to the problem of decision support in a simulation environment prepared for the air traffic control service. The limitations resulting from the functionality of the airport have been presented. In addition, the “integration” problems resulting from the movement of aircraft on the apron have been presented. The article outlines optimization problems such as minimizing the total taxiing time, taking into account the waiting time for the start of the runway, minimizing the time elapsed from the first taxiing to the end of taxiing by the last aircraft or multi-faceted functions, including, for example, penalties for deviations from the schedule of take-off / landing operations, failure to keep the CFMU time slots, or for too long taxiing cycles. The article presents restrictions on taxiing of aircraft, integration with other airport operations, decision problems and applied algorithms, groups of restrictions on taxiing of aircraft, scheduled flight table, dependencies between individual operations, positioning of aircraft.

Schlüsselwörter

  • air traffic control
  • aircraft operations
  • airport
Uneingeschränkter Zugang

Comparative Analysis of the Fuel Consumption of Vehicles Equipped with Various Types of Automatic Transmissions

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 119 - 124

Zusammenfassung

Abstract

The growing number of vehicles moving on Polish roads equipped with various types of automatic transmissions prompted the authors of this publication to carry out research to assess the impact of the use of this type of transmission on the fuel consumption of these vehicles. The presented article presents a comparative analysis of the fuel consumption of vehicles of different manufacturers equipped with automatic transmissions moving in specially prepared driving cycles for research purposes. In the developed driving cycle, the vehicle speed was gradually increased every 10 km/h, maintaining each speed for a period of at least 30 seconds in order to stabilize the measurement results. The tests were carried out for various load stages of the drive system. Load differentiation was made by simulating driving in the prepared cycle for simulated different slopes of the road. The tests were carried out on the MAHA MSR500 chassis dynamometer, and the obtained results for the vehicle moving in automatic mode, where the transmission controller selected the gear ratio according to the programmed algorithm, were compared with the vehicle's fuel consumption for the vehicle gear selected by the driver in the driving cycle. The control software used to test the chassis dynamometer allows taking into account the increasing resistance of traffic along with the increase of vehicle speed, which greatly approximates the simulated conditions in the laboratory to the conditions on the road. The main purpose of this publication is to check whether using automatic transmissions or other control algorithm of these gears can achieve a reduction in fuel consumption.

Schlüsselwörter

  • automatic transmission
  • fuel consumption
  • control algorithm
  • CVT
  • automotive powertrain
  • road slope
Uneingeschränkter Zugang

Thermal Analysis and Thermovision Laboratory Tests of Electric Brakes

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 125 - 131

Zusammenfassung

Abstract

The purpose of this article was to show two thing thermal issues theory and thermovision tests in the laboratory. The main idea of this article was to describe the thermal issues theory of interesting problem base on the thermovision tests of new type electric brake prototype. After the creation of new product the designer needed to know how behave the prototype of the brake during tests with higher energy which could increase the temperatures on the object in our case of the electric brake prototype. The first step in that kind of issues was thermal analysis, which is very useful to define and subscribe the thermal issues. The second step it was measurement of the temperature, which was really significant during the electric brake tests. It was really important to check the temperature of engines. If there was some influence to the brake during braking. One of the method was using special thermal camera. The camera was checking the temperature during whole test after beginning the test to the end of the trial. The full spectrum of the temperature allowed the author to verify if there was some influence of temperature to the new electric brake prototype. The thermocouple was other type of sensors, which was normally used in our laboratory methodology to check temperature during the test. The pyrometer was other type of the method, which was used to measure the temperature after the test. The results of this measurement were subscribed in this article.

Schlüsselwörter

  • laboratory testing
  • electric brake
  • temperature tests
  • braking process
  • thermovision
Uneingeschränkter Zugang

The Application of Genetic Algorithm in the Assignment Problems in the Transportation Company

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 133 - 140

Zusammenfassung

Abstract

The article presents the problem of the task assignment of the vehicles for the transportation company, which deals with the transport of the cargo in the full truckload system. The presented problem is a complex decision making issue which has not been analysed in the literature before. There must be passed through two stages in order to solve the task assignment problem of the vehicles for the transportation company. The first stage is to designate the tasks, the other one is to determine the number of the vehicles that perform these tasks. The task in the analysed problem is defined as transporting the cargo from the suppliers to the recipients. The transportation routes of the cargo must be determined. In order to solve the task assignment problem of the vehicles, the genetic algorithm has been developed. The construction stages of this algorithm are presented. The algorithm has been developed to solve the multi-criteria decision problem. What is more, the algorithm is verified by the use of the real input data.

Schlüsselwörter

  • assignment problem
  • genetic algorithm
  • multi-criterion optimization
  • transportation company
Uneingeschränkter Zugang

CFD Simulations as a Support of Experimental Research in a Rapid Compression Expansion Machine Facility

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 141 - 147

Zusammenfassung

Abstract

The main aim of this study to reproduce methane combustion experiment conducted in a rapid compression-expansion machine using AVL FIRETM software in order to shed more light on the in-cylinder processes. The piston movement profile, initial and boundary conditions as well as the geometry of the combustion chamber with a prechamber were the same as in the experiment. Authors by means of numerical simulations attempted to reproduce pressure profile from the experiment. As the first step, dead volume was tuned to match pressures for a non-combustion (air-only) case. Obtained pressure profile in air compression simulations was slightly wider (prolonged occurrence of high pressure) than in the experiment, what at this stage was assumed to have negligible significance. The next step after adjusting dead volume included combustion simulations. In the real test facility, the process of filling the combustion chamber with air-fuel mixture takes 15 s. In order to shorten computational time first combustion simulations were started after the chamber is already filled assuming uniform mixture. These simulations resulted in more than two times higher maximum pressure than recorded in experiments. It was concluded that turbulence decays quickly after filling process, what was also confirmed by next combustion simulations preceded by the filling process. Then the maximum pressure was significantly decreased but still it was higher than in the experiments. Based on the obtained results it was assumed that the discrepancy noticed in air cases is further increased when combustion is included. Moreover, the obtained results indicated that pre-combustion turbulence level is very low and suggested that either piston profile movement is not correct or there is high-pressure leak in the test facility.

Schlüsselwörter

  • AVL FIRE
  • self-ignition
  • RCEM
  • CFD
  • knocking combustion
Uneingeschränkter Zugang

Analysis of Hazards Occurring During the Use of Hydrazine

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 149 - 154

Zusammenfassung

Abstract

The article presents the safety issue bonded to the Polish Air Force F-16 multirole aircraft. The authors pointed out the issue of fuel used for emergency supply system of these aircrafts. The article emphasized the fact that these aircrafts require special fuel with designation H-70, which is 70% aqueous solution of toxic hydrazine. For this reason, the rescue services of Polish Air Force bases where Polish F-16 are stationed had to be adjusted accordingly. Just as importantly, authors noticed that in the event of an emergency landing of this aircraft at different airports could receive difficulties associated with the possible leakage of hydrazine, or its neutralization in the absence of specialized Hydrazine Response Team, which are part of the Airport Rescue Group. After the introduction of new aircraft for use in the Polish Air Force (in this case F-16 multirole aircraft), it is necessary to analyse the safety of their use in the context of potential places on which they can land. This is related, among others, to the safety of managing liquid fuels. In the case of F-16 aircraft, one must bear in mind besides the F-34 fuel, also hydrazine (H-70). The article presents a functional diagram of EPU system of emergency power supply EPS of F-16 multirole aircraft.

Schlüsselwörter

  • aviation fuel
  • hydrazine
  • airport rescue group
Uneingeschränkter Zugang

Influence of Geometric Characteristics of the Bomb-Fluger System on its Dynamics

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 155 - 163

Zusammenfassung

Abstract

The article presents the results of numerical simulations of the bomb-fluger system drop. This system consists of two rigid bodies – a bomb and a fluger, which are connected by a biaxial joint. For the analysis, an author's program was used to simulate the bomb-fluger system drop. Influence of the characteristic points of the system on its stability and dynamics was investigated. Particularly, locations of a bomb mass centre, a fluger mounting point, a fluger aerodynamic focus were tested. The article presents a model of the examined bomb in the wind tunnel, characteristic points of a bomb-fluger system, waveforms of values rate of change angles and the values of angles for different distances, waveforms of values of the angle of nutation and the pitch angle of the fluger relative to the bomb, diagrams of examined points of the location of the centre of the mass and pressure of the fluger, waveforms of values rate of change angles and the values of these angles for different locations of the centre of the mass of the fluger, waveforms of values of the angle of nutation and the pitch angle of the fluger relative to the bomb for different locations.

Schlüsselwörter

  • guided bombs
  • bomb-fluger system
  • aerodynamics simulations
Uneingeschränkter Zugang

The Evaluation of the Efficiency of Active Control System for Aerial Bomb

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 165 - 174

Zusammenfassung

Abstract

The article presents the results of numerical simulation of a laser-guided bomb, which is dropped in calm weather conditions. The prototype of such a bomb was developed at the Air Force Institute of Technology. It was a result of the modification process of the classical training bomb. The modification consisted of building on the bomb's board a detection system to track targets that are designated by laser and a control system to adjust bomb’s glide path to precisely strike the target. In the simulation research, geometric and mass characteristics of the classical training bomb were used. Aerodynamic characteristics of the bomb have been determined using commercial software PRODAS. Using the mathematical model of the bomb spatial motion and model of the laser detection system series of simulations were performed. The main goal was to determine the effectiveness of the adopted construction solution. Therefore, simulations were performed for various initial positions of the bomb and fixed position of the target. It allowed finding the set of control laws coefficients giving the most accuracy of the bomb. The influence of structural modifications of the detection system on the possibility of effective detection and location of the target was also investigated. In the article, exemplary results of numerical calculations performed with the author's software are also shown.

Schlüsselwörter

  • simulation
  • PID controller
  • laser-guided bombs
Uneingeschränkter Zugang

Numerical Modelling of Combustion Process with the Use of ANSYS FLUENT Code

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 175 - 186

Zusammenfassung

Abstract

The article presents the modelling of the combustion process of liquid fuels using professional ANSYS FLUENT software. This program allows modelling the dynamics of compressible and incompressible, laminar and turbulent flows as well as heat exchange phenomena with occurrence and without chemical reactions. The model presented in the article takes into account the influence of the gas phase on the liquid phase during the fuel combustion process. The influence of velocity and pressure of the flowing gas and the type of flow has a significant impact on the combustion of liquid fuels. The developed model is fully reliable and the presented results are consistent with experimental research. The occurrence of a laminar sublayer in a turbulent flow was confirmed, and the thickness of this layer and the turbulent layer significantly influences the course of the combustion process. The use of the flat flow model reflects the basic phenomena occurring during the combustion of liquid fuels under turbulent conditions. The use of the program for flows with different flow velocity profiles is justified. It gives important information about the processes taking place during the combustion of liquid fuels. The results of numerical tests are presented graphically. The article presents graphs of velocity field, absolute pressure, power lines, temperature and density.

Schlüsselwörter

  • liquid fuels
  • combustion processes
  • turbulent flow
  • combustion process model
  • ANSYS FLUENT
Uneingeschränkter Zugang

Researches of a Combustion Engine Fuelled with a Fuel-Water Microemulsion

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 187 - 196

Zusammenfassung

Abstract

The emulsion is a mixture of two or more insoluble liquids. Microemulsion is the emulsion with particles dimension in a range of one micrometre and smaller. Such a microemulsion of water and diesel fuel will create a novel quality and allows one to simultaneously achieve environmental and economic effects, as well as eliminate the ad-verse impact of normal emulsions, or adverse effects of water injection into the engine intake system or directly into the combustion chamber, as well as the sequential injection of water directly into the combustion chamber. Application of microemulsion of water and diesel to fuel diesel engine positively affects the combustion process through the catalytic impact of microparticles of water, and improves the process of preparation of the microemulsion injection into the combustion chamber as a result of water microparticles’ microexplosions. This article presents the investigation results of an internal combustion engine fuelled by an emulsion of water and diesel fuel and fuelled by emulsion of FAME and water. It therefore seems appropriate to a strong increase in the degree of dispersion of water droplets in the emulsion by applying the methods to obtain the size of water droplets on nanometric range. This should dramatically improve both the stability of emulsion and its influence on the chemical effects of combustion in diesel engine.

Schlüsselwörter

  • combustion engine
  • combustion processes
  • ecology
  • fuel-water microemulsions
Uneingeschränkter Zugang

The Use of Laser Equipment to Optimize the Operating Parameters of the Fuel Injector of Combustion Engine

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 197 - 206

Zusammenfassung

Abstract

The conducted tests were aimed at determination of the drop diameters and shaping of the velocity field at different configurations of the test injector. The test results allowed defining the relationship between the injector configuration and the distribution of velocities and dimensions of drops in the fuel stream. The effect of the fuel viscosity and injection pressure on the dimensions of fuel drop diameters and the distribution of the velocity field of drops in the stream were tested. The tests were carried out on a special test rig with a fixed volume chamber. The measurements were carried out with the use of laser Doppler measurement systems (PDPA, LDV). The tests were conducted for seven different fuel types varying in viscosity and surface tension. In addition, the injection pressure from 50 MPa to 130 MPa was applied. The test results allowed determining the relationship between the injector structure configuration, fuel types and fuel additives, and the distribution of velocity and an atomisation spectrum of drops in the fuel stream, and the air impact on the fuel stream.

Schlüsselwörter

  • combustion engine
  • fuel injection
  • laser methods
  • size drop distribution
Uneingeschränkter Zugang

Technical and Economic Analysis of Various Solutions of Fuel Supply Systems in Marine Diesel Engine of Ships Sailing in the Control Emission Areas (ECA)

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 207 - 216

Zusammenfassung

Abstract

In the article, legal norms regarding the reduction of sulphur content limits in exhaust gases in special areas were presented. Then an overview of various solutions for supplying the marine engine with heavy fuel, distillation fuel and gas was made. In addition, the problem of using low-sulphur fuels in internal combustion engines was described. The presented solutions are a response to the latest provisions being part of the VI Annex of the MARPOL Convention, which entered into force on 01.01.2015. These provisions constitute that sulphation of fuel used in Emission Control Areas (ECAs) may not exceed 0.1%. Then, to meet the requirements, the conditions of using heavy fuels for supplying diesel engines were presented. Individual solutions such as the use of low-sulphur fuels, exhaust gas scrubber assembly, and the supply of liquefied natural gas (LNG) from the technical side were shown. Besides, the advantages and disadvantages of each of them were also indicated. In the following part, the economic analysis of the selected ship was made. Its purpose was to evaluate economically in the assumed time of operation, and then select the optimal solution for a given unit. For the comparative analysis, the use of low-sulphur fuels was used; the assembly of the scrubber, as well as the adaptation of the unit to use liquefied natural gas (LPG). The article was finished with conclusions; the most important of them is that the use of fuels with reduced sulphur content is the most expensive solution for the selected ship. The cost of the remaining solutions is at a comparable level, but they require greater interference in the ship’s construction.

Schlüsselwörter

  • environmental protection
  • sulphur compounds
  • power engines
  • marine scrubbers
  • shipping
Uneingeschränkter Zugang

Analysis of Abrasive Wear of Selected Aircraft Materials in Various Abrasion Conditions

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 217 - 222

Zusammenfassung

Abstract

The use of composite materials is continuously increasing in modern transport. This process is especially noticeable in aviation. The mass percentage of epoxy resin composites in contemporary aircraft constructions is usually higher than 50%, and these materials must meet increasingly demanding requirements. In these circumstances, in addition to mass and strength, it is necessary to predict other properties of the material, such as abrasion resistance. The article presents the analysis of the process of abrasion of carbon fibre reinforced polymers reinforced with various fillers. Straight carbon fibre mats were used for the tests. In addition, powders of pumice, alumina, silicon carbide, and glass microspheres at various concentrations in relation to the matrix were used as fillers. In order to investigate the influence of external factors on the abrasion process, each group of samples was subjected to abrasion under different external conditions: in an insulated environment, in the presence of water and loose abrasives: brown fused alumina (BFA) and white fused alumina (WFA). The measurements were carried out using a precision balance and an electron microscope. The results allow concluding on which kind of filler and in what concentration contributes to improvement of the abrasion resistance of the composite material the most. In addition, it was found that the conditions in which abrasion occurs have a very large impact on the course of this process.

Schlüsselwörter

  • composite materials
  • tribology
  • carbon fibre reinforced polymer (CFRP)
  • aerospace materials
Uneingeschränkter Zugang

The Influence of Granulation and Content of Polyester-Glass Waste on Properties of Composites

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 223 - 229

Zusammenfassung

Abstract

Glass fibre reinforced composites are used in many branches of industry. Polyester-glass laminates serve as structural material in shipbuilding (e.g. hulls of units, superstructures), in railways, automotive (e.g. elements of car bodies and interior fittings, roofs of wagons, cisterns) or aviation (e.g. aircraft fuselages, fuel tanks, completion beaks and ballasts). Factors affecting the increase of their use include low specific gravity, optimal strength properties, corrosion resistance. This is associated with a large amount of post-production and post-use waste. The recycling problem of these materials remains unresolved. The article presents the technology of processing polyester-glass waste in order to obtain a recycle with a specific granulation. The selected technology for the production of layered composites with reinforcement in the form of recycle is described. For testing, granulation was selected for 1.2 and 3 mm, as well as content: 0%, 10%, 20% and 30%. Using the water-cutting method, samples were prepared according to the standard static tensile test for plastics. The tests were carried out using a universal testing machine as well as an extensometer for samples with granulation of 1.2 mm and 3 mm, as well as the selected recycled percentage. Obtained results of the research indicated that granulation as well as content affects the strength properties of composites. As the granulation increases, at the same content, the material gains less deformation. The increase in the amount of the recycle reduces the strength properties of the material, and also due to the decrease in the deformation value - the material becomes brittle.

Schlüsselwörter

  • recycling of composites
  • polyester-glass waste
  • tensile test
  • strength properties
Uneingeschränkter Zugang

The Possibility of Modifying the Lubricity of Transmission Oils in Industrial Gears

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 231 - 237

Zusammenfassung

Abstract

The study deals with the issue of durability extension of multi-phase gears working under temporary or constant loading. The tests were performed for transmission oils used in power transmission systems of beet washers of DC type used in sugar plants. The lubricity parameters of oils and the possibilities of their modification through introduction of low-friction additives to the oil were studied. Additionally, the noise level emitted by working gears was measured before and after addition of the modifier. Lubricity tests were performed on semi-Timken apparatus, on which friction pairs friction roller- roller were tested with the use of oils extracted from the gear. SoundMeter application with MIC002 microphone adaptor was used for measurement of the noise level emission. Tests results have confirmed efficiency of the modifiers as higher values of friction loading were obtained and the noise emission level was reduced. It has been proven that in real operation systems, there is a possibility to increase the value of transmission oil lubricity parameters, which has a direct impact on durability of friction pairs of a gear during its operation.

Schlüsselwörter

  • lubricating oils
  • gear box
  • friction
  • lubrication
  • boundary layer
  • low friction additives
  • acoustic emission
Uneingeschränkter Zugang

Application of Similarity Method of Distance Courses Describing the Elements Content in Typical Cement Concrete

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 239 - 246

Zusammenfassung

Abstract

The article concerns the use of similarity analysis of distance course in the internal area of cement concrete intended for airfield pavements. Research procedure was presented and the obtained laboratory tests results were discussed. The contents of diversified elements in four zones (cement matrix, contact area between air pores and cement matrix, contact area between fine aggregate and cement matrix and contact area between coarse aggregate and cement matrix) were specified by using scanning electron microscope. Based on the results obtained diagrams similarity of the analysed of areas in the concretes were prepared. The purpose of this article has been the assessment of an opportunity to apply the analysis of similarity of distance courses with respect to cement concrete intended for airfield pavements. The scope of article consisted of two stages. The analysis included cement concretes intended for airfield pavements, in compliance with requirements. The thermal analysis method was used; the selected concrete components were determined by means of quantitative method. The occurrence of crystalline stages was determined using X-ray diffraction method. Internal structure of concrete composite was assessed with the scanning electron microscope.

Schlüsselwörter

  • transport
  • airfield pavements
  • cement concrete
  • concrete microstructure
  • analysis of similarity
Uneingeschränkter Zugang

Python Programming Language as a Tool for Creating Three-Dimensional Figures of Glider Aerobatics

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 247 - 253

Zusammenfassung

Abstract

The article presents the possibilities and validity of the implementation in the field of developing mathematical models for aerobatics trajectory. Proposing a catalogue of three-dimensional figures and those described mathematically will allow improving judging and scoring level, as well as the art of piloting in aerobatics. In the first chapter, article describes the processes of aerobatic flight, judge evaluation method and the current state of technology supporting the scoring process. The second chapter presents the capabilities of the Python programming language, which will be a tool for the construction of three-dimensional models. The third chapter of this article is a description of the comparative analysis of ideal trajectories and obtained in real flight. This chapter also demonstrates the validity and necessity of introducing new standards for assessing aerobatic flights. Aerobatics flights and judging, intelligent system to control aerobatic flights, three-dimensional models of aerobatic flights are presented in the article. The article concerns on use modern technologies to support the judges during the competition. The introduction of ASSD + PL system and the possibility of implementing designed models of aerobatic figures open new paths for improving the art of pilotage and arbitration.

Schlüsselwörter

  • aerobatics
  • general aviation
  • fly trajectory
  • mathematical programming
Uneingeschränkter Zugang

The Initial Analysis of the Aerodynamic Characteristics of a 3D Printed Model of an Aircraft

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 255 - 262

Zusammenfassung

Abstract

The aerodynamic research into models of an aircraft aims at creating the main characteristics of aerodynamic forces and moments and the aerodynamic characteristics of coefficients of aerodynamic forces and moments, based on real dimensions. The method of 3D printing was used to create a model of an aircraft. The model with the previously set printing parameters and commands for a 3D printer, in the right order, was imported into MakerBot Print. The final stage was printing the model. The printed components of the model of an aircraft were imperfect due to the incorrectly set printing parameters. The model with the previously set printing parameters and commands for a 3D printer, in the right order, was imported into MakerBot Print. The final stage was printing the model. The printed components of the model of an aircraft were imperfect due to the incorrectly set printing parameters. The printing parameters were corrected in the next printing sessions so the surfaces of the components were good enough and grinding was unnecessary. Some excess material was removed in each of the printed components, and the slots were cleaned. Then, the individual models were put together.

The article describes the technique of creating a model of an aircraft to map its exact geometry for experimental wind tunnel research. 3D printing enables us to experimentally investigate a created geometry, in particular to investigate further prior to releasing an aircraft to service. The 3D model employs the model created in line with the previous CFD analysis.

Schlüsselwörter

  • air transport
  • simulation
  • wind tunnel
  • experimental analysis
  • gyroplane
Uneingeschränkter Zugang

Computational Modelling of the Fuel Injection and Combustion in a Diesel K6 Rotary Engine

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 263 - 276

Zusammenfassung

Abstract

This paper outlines the methods and results of computations completed using the ANSYS Fluent code modelling the fuel injection and combustion within the K6 engine, a new form of rotary engine in which the fuel is injected in an arc across the top of the cylinder. The model uses the DPM Model in conjunction with a dynamic mesh and non-premixed combustion models to treat the injection as liquid diesel evaporating to C12H23. The outcomes of this model are presented in images displaying the distribution of temperature, and fuel and CO2 concentrations. The limitations pertaining to the maximum injection angles are also studied. The simulation is found to be effective and the results suggestive of successful, clean and complete combustion while presenting some matters, which require further investigation. The article presents temperature within the combustion chamber at various crank angle degrees, ) velocity of fluid within the combustion chamber, effects of impingement with injector offset on temperature and fuel concentration, fuel concentration demonstrating impingement, in cylinder temperature curve

Schlüsselwörter

  • combustion engine
  • combustion process
  • combustion factors
  • fuel injection
  • ANSYS Fluent code
Uneingeschränkter Zugang

Modelling of Physical Phenomena in the Vertical Velocity Measuring Circuit for Process of Designing the SWPL-1 Helmet-Mounted Display System

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 277 - 284

Zusammenfassung

Abstract

The article presents the selected methods of identifying static and dynamic properties of the measuring paths to the extent necessary for the proper integration of on-board systems with the helmet-mounted flight parameter display system. It presents the methods of identifying static and dynamic properties of the WR-10MK on board variometer as one of more difficult identification elements. Its identification was carried out on the basis of the basic dependencies of the International Standard Atmosphere and the instruments construction’s parameters. It built a mathematical model describing the physical phenomena associated with vertical speed measurement. This model differs from the models found in the literature in terms of detail and description accuracy. On this basis, in the Simulink environment, it built a simulation model corresponding to its mathematical model. The non-linear model was the starting point for the construction of the linearized model based on the operator transmittance. The developed models were evaluated for errors of vertical speed’s dynamic indications. This allowed assessing the usefulness of the individual models for further works on ensuring the correlation of indications of the on-board variometer and the SWPL-1 helmet-mounted flight parameter display system. The presented simulation models include design details, as well as the characteristics of technological errors and disturbances of a stochastic nature. Another approach to the issue of identification is to use the characteristics provided by the manufacturer in the form of approximate characteristics of a module.

Schlüsselwörter

  • transport
  • avionics
  • helmet-mounted display systems
  • errors of the vertical velocity measurement
Uneingeschränkter Zugang

Application of Multi-Criteria Optimization to Choose Variants of Hardware Architecture for the SWPL-1 Helmet-Mounted Display System

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 285 - 292

Zusammenfassung

Abstract

The paper presents the structure and basic properties of the SWPL-1 helmet-mounted flight parameter display system, constructed for the Mi-17 helicopter with analogue systems and on-board instruments. It describes the basic components of the SWPL-1 system and on board components cooperating with the SWPL-1 system necessary to ensure the imaging system’s operation (including the ADU-3200 central unit for aerodynamic data and the GPS-155XL satellite signals receiver). It presents the architecture, the principle of operation, and the main constituents of the SWPL-1 helmet-mounted flight parameter system, as well as the standards of data transmission used in digital communication between the SWPL-1 system and on-board systems (installed on the Mi-17 helicopter). It describes the scope and manner of pilot and navigation data presentation as well as control of drive unit operation parameters in detail. It presents selected optimization methods for tasks executed in the helmet mounted system’s life cycle. The particular stages of the life cycle were described in detail, from the earliest stages of needs identification, through the analytic and conceptual phase, then the implementation stage, and ending with the operation stage. It introduces tasks for optimization and related methods into the process of creating the new system at every stage of its implementation. It presents one of the methods of multi-criteria optimization based on the experts’ assessment of choice of a variant of the helmet-mounted flight parameter display system’s hardware architecture in detail.

Schlüsselwörter

  • transport
  • avionics
  • helmet-mounted display systems
  • hardware architecture
  • multi-criteria optimization
Uneingeschränkter Zugang

Using Thermovision for Temperature Measurements During Turning Process

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 293 - 298

Zusammenfassung

Abstract

In metal cutting industries, machining processing, especially turning operation is very basic type of machining. For certain processes in manufacturing, it is favourable and necessary to have certain knowledge about heat generation and temperature rise (including average and maximum temperature) during machining process. Increment in maximum temperature at clearance face or at rake face of cutting tool causes the reduction in life of tool. Similarly, the quality of machined surface, a metallurgical structural alteration in tool and workpiece material also depends on the maximum temperature, temperature gradient and cooling rate of both tool and workpiece. Certain physical and chemical reactions that are developed during the cutting process are directly connected with tool wear, power consumption, surface roughness on work piece material and cutting temperature. The natural low of thermal energy gives significant relationship between cutting temperature and cutting parameters in order to improvement of cutting tool’s wok efficiency, quality and accuracy. The heat distribution in cutting tool, in formed chip and in workpiece material strongly depends on (mechanical and chemical) properties of cutting tool and workpiece material, cutting speed, depth of cut, feed rate, nose radius, geometry of tool, type of coolant used and other parameters. This work presents some results of research done during turning steel 235JR realized on conventional lathe CDS 6250 BX-1000 with severe parameters. These demonstrate the necessity of further, more detailed research on turning process temperature, realized for different materials.

Schlüsselwörter

  • lapping
  • infrared measurement
  • lapping plate temperature
  • lapped surface quality
Uneingeschränkter Zugang

Analysis of Changes in Traffic Rules and Assessment of Their Impact on Road Traffic Safety

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 299 - 308

Zusammenfassung

Abstract

Road safety is an important social issue. Hence, changes in road traffic rules have a large influence on travel safety improvement. One of the major issues to be addressed is the speed limit of motor vehicles and radar speed measurements. Moreover, road traffic rules impose the obligation to wear safety belts during driving, carrying children in car safety seats and they put a ban on drink driving as well as driving under the influence of other intoxicating substances that have a negative influence on the driver’s physical condition and driving skills. This study analyses changes in traffic rules and provides assessment of the way they affect road traffic safety in Poland. The study presents an analysis of the issues connected with road vehicle operation and safety of the passengers including: wearing safety seat belts, use of children car safety seats, vehicle lighting, speed limit. Such issues as the proposed changes in breathalyzer use and implementation of safety systems to provide road users with safety have been addressed.

Schlüsselwörter

  • transport
  • road transport
  • traffic rules
  • safety
  • vehicle operation
Uneingeschränkter Zugang

Possibilities of Extension of Gear Oil Service Life in Rail Vehicles

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 309 - 316

Zusammenfassung

Abstract

The study deals with the results of operational tests of gear oils used in a regional railway transport system. The character of the aging process and the impact of gear oil operation on the main factors determining further usability of gear oil have been defined on the basis of the results of carried out tests. It was proved that transport systems lack reliable convenient diagnostic methods for gear oil used during the process of operation. One of the criteria taken into consideration in decision-making is the period of oil change imposed by the gear manufacturer. The long process of oil application is accompanied by physicochemical changes, which cause degradation of its properties. This phenomenon is referred to as oil aging. This fact can cause loss of viscosity, increase in the amount of pollution, and in effect a decrease in the ability to provide a durable boundary film. The lubricating ability of oil decreases as well. An increase in the amount of pollution is caused by interaction of the collaborating friction elements and by pollutants coming from the gear environment. These changes are of permanent character and reflect the state of new characteristics referred to as operational characteristics. Gear oils have a certain lubricating ability, which is a critical parameter. This study is an attempt to find a way of the oil service life extension and convince the propulsion systems manufacturers that reduction of costs connected with rail vehicle maintenance does make sense.

Schlüsselwörter

  • transport
  • rail vehicle
  • lubricity
  • ignition temperature
  • concentration of wear products
  • kinematic viscosity
Uneingeschränkter Zugang

Analysis of LDV Operation Manner in Terms of its Environmental and Economical Indexes

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 317 - 323

Zusammenfassung

Abstract

Environmental protection is becoming an increasingly important issue in every area of life. In recent times, a great emphasis has been placed on reducing the negative impact of automotive on human health at every stage of the vehicle's life. The most common impact of cars on the environment is the emission of pollutants from the exhaust system, created during the combustion of fuels in internal combustion engines. For this purpose, legislators introduce emission standards that must be met at the stage of vehicle approval for a given market. To meet these requirements, vehicle manufacturers modify the design of the drive units, body, and chassis to reduce weight and improve aerodynamic properties. This approach is methodologically correct because it is possible to compare the results obtained for different vehicles, but in real operation the level of harmful exhaust compounds, emissions and fuel consumption depend very much on the way the vehicle is used. As a manner of operation one can understand a variable load in the form of passengers or cargo, driving style, share of urban, extra-urban and motorway driving, terrain formation, ambient temperature and others. This article addresses issues related to the assessment of the impact of the light commercial vehicle operation manner on fuel consumption and the emission of harmful exhaust compounds. The problem was analysed in terms of the difference in vehicle load and driving style. Exhaust emission measurements were carried out using PEMS (Portable Emission Measurement System) analysers, which are state of the art devices for measuring exhaust emission in real operating conditions, called RDE (Real Driving Emissions).

Schlüsselwörter

  • exhaust emission
  • road transport
  • RDE
  • PEMS
  • ecodriving
Uneingeschränkter Zugang

Modelling of a Permanent Magnet Motor with an Inverter in a Drive System of a Car – Part II

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 325 - 335

Zusammenfassung

Abstract

The article presents a mathematical model of a permanent magnet motor, powered by a three-phase source of sinusoidal voltage, and a control method. Cooperation between numerical integration algorithms in the differential equation system of the motor and an inverter has been verified. The results of numerical simulations are presented in a graphic form. This article is an extension of the publication [12], in which a model of a drive system was proposed, consisting of: a battery, a supercapacitor and a method of controlling these energy sources during a driving cycle of a vehicle. For vector control, the mathematical model of a synchronous machine in the dq coordinate system is the most common one. The most important feature of this control method is the fact that the iq component of the rotor current vector determines the value of motor torque, and the component id – the value of magnetic flux. In the article, the emphasis is put on how inverters work. Their basic task is to generate such currents iabc or voltages uabc to obtain torque without ripples. It leads to development of different control concepts for achieving this goal, which are related to the modelling of magnetic fluxes in a stator and in an inverter.

Schlüsselwörter

  • electrical machines
  • permanent magnet motor
  • inverter
  • electric drive control system
Uneingeschränkter Zugang

Impact of the Geometry Accuracy of the Cycloidal Gear Output Shaft with Pins of the Efficiency and Vibrations

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 337 - 345

Zusammenfassung

Abstract

Cycloidal gear is characterized by [2]:

– Large ratio (up to 171:1) from one stage of reduction, which minimizes the weight and dimensions of the reducer.

– Minimizing the centrifugal forces as the only high-speed element is the input shaft with an eccentric bearing.

– Minimizing internal clearance due to simultaneous meshing of a large number of teeth. In contrast to gears with involute teeth, 10-50% of teeth are found in cycloidal gears with simultaneous meshing. It depends on the size of the gear and the load. The minimum number of teeth engages when running in bulk.

– Low noise and low vibration for large torques and variable speeds.

– High efficiency in a wide range of loads, because rolling elements are used in every place responsible for the transfer of torque.

– Permissible load up to 500% of the rated torque.

All above mention point lead into long-term and trouble-free operation, however the above features require high accuracy. The article described comparison of efficiency, vibration and noise obtained for 3 cycloidal gear modules:

1. Two-disc gear with single rollers for both discs (Chmurawa prototype [1]).

2. Three-disc gearbox with separate rollers for each disc (new idea) with gear components: output shaft with pins, housing with rollers (wheel with internal tooting), and input shaft, made with the manual lathe.

3. The same three-disc gearbox with output shaft with pins made with the CNC. Different levels of accuracy and thus corresponding vibration patterns were obtained.

Schlüsselwörter

  • cycloidal gear
  • efficiency
  • vibrations
Uneingeschränkter Zugang

Electrical Properties Study of Fibre Reinforced Polymeric Materials Used in Aircraft Structures

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 347 - 353

Zusammenfassung

Abstract

Aircraft are exposed to lightning strikes. Lightning strike protection (LSP) devices involve additional weight of the aircraft. Therefore, multifunctional materials that allows the conductivity of electrical current and, simultaneously, holds the mechanical properties required to withstand the typical conditions for an aerospace material are widely researched. A typical resin used in aviation is an insulator, so main research is done to reduce its resistance. On the other hand, the type of reinforcement can have a large influence on the electrical conductivity in the plane of reinforcement. The aim of the article is to evaluate the effect of the type and the basis weight of reinforcement on the electrical conductivity. For this purpose, with the use of a hydraulic press, different four-layer composites based on epoxy resin were produced. Each differing is in combination of carbon, glass layers and their basis weight (from 48 kg/m2 to 245 kg/m2). The measuring proceedings were carried by an RMS multi meter and, more accurate, by an LCR meter with 4 selectable test frequencies. The measurements were made both along the strand fibres and at a 45-degree angle. The results made it possible to determine which reinforcement of aircraft composites should be selected at the aircraft design level to provide increased electrical conductivity along the reinforcement fibres and thus influence one of the factors affecting the protection of the aircraft against the effects of lightning.

Schlüsselwörter

  • composite materials
  • electrical conductivity
  • carbon fibre reinforced polymer (CFRP)
  • glass fibre reinforced polymer (GFRP)
  • aerospace materials
  • lightning strike protection (LSP)
Uneingeschränkter Zugang

High Voltage Batteries Diagnostic

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 355 - 360

Zusammenfassung

Abstract

Hybrid vehicles history begins between XIX and XX century because then has been constructed first hybrid vehicle project. The first men who produced electric propulsion mounted in front hubs connected with generator powered by spark ignition engine was Ferdynand Porsche. Vehicle was called Lohner – Porsche Electromobile. The first en masse produced hybrid vehicle was the first generation Toyota Prius. These model premiere was in 1996, and production started one year later. Vehicle was equipped in 1,5 dcm 58 hp spark ignition engine with added electric propulsion generated 40 mechanical hp. There has been mounting 72 hp spark ignition engine and 44 hp electric generator since 2000. Fuel consumption of these model was 5 liter on 100 km. Beginning XXI century 95% hybrid vehicles were Toyota Prius. The biggest competitor of Toyota Prius was Honda Insight. Lexus and Mercedes started producing hybrid vehicles few years later. The most popular brands selling hybrid vehicles are Toyota and Lexus – Toyota Motor Corporation.

Article describes high voltage battery example diagnostic possibilities in a hybrid or electric vehicle. Constructing vehicle models using two propulsion systems (spark ignition engine and electric generator) cause development and increase control system devices. The measurements has been made by using various diagnostic devices for example: diagnostic scanner mega macs 66, high voltage battery tester. Reading faults code is not enough so it is necessary to use data list what describes this article.

Schlüsselwörter

  • hybrid vehicles diagnostics
  • high voltage battery
  • HV battery test
Uneingeschränkter Zugang

Characteristic Features of the Process of Growth in the Mileage of Hybrid Vehicles

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 361 - 368

Zusammenfassung

Abstract

For a few years, the sales of motor vehicles with hybrid drive systems (referred to as “hybrid vehicles” or “HVs”) have been rapidly growing. However, there is a lack of information about the intensity of operation of vehicles classified in this category, which is completely new. A calculation procedure has been presented that enabled evaluation of the HV mileage growth rate. An analysis of this rate provides grounds for forecasting the changes that are likely to take place in the fleet of motor vehicles, such as the progress in the process of replacement of conventional vehicles with vehicles with alternative drive systems, and this may be a basis for predicting the reduction in fuel consumption and exhaust emissions. Models of the HV mileage growth process have been defined for three different countries. They indicate high mileage growth rates in the initial period of vehicle operation, e.g. until the fourth year of operation of the Auris H cars. The highest mileage growth rates in this period were observed in the Netherlands and Poland. In Germany, this rate was lower by 41%. Significant differences in the intensity of vehicle operation have been observed between the behaviour of HV owners in the countries under analysis. A considerable drop in the annual HV mileage as early as in the fifth and sixth year of vehicle operation is an alarming signal.

Schlüsselwörter

  • hybrid vehicles
  • mileage of hybrid vehicles
  • estimation of mileage growth models
Uneingeschränkter Zugang

Reduction of Pressure Rise Rates in Boosted HCCI Engine Using Advanced Valve Actuation Strategies

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 369 - 376

Zusammenfassung

Abstract

Homogeneous Charge Compression Ignition (HCCI) is a promising low temperature combustion technology which offers high fuel efficiency and extremely low exhaust emissions. However, there are still some pending issues to be resolved before the technology will achieve mass production level. Namely, combustion controllability should be improved and HCCI operating range should be widen. The latter is constrained by excessive combustion rates under high loads. In this study, advanced variable valve actuation strategies were applied to control auto-ignition timings and combustion rates. The examinations were conducted using single-cylinder research engine fuelled with directly injected gasoline. The HCCI combustion was achieved using negative valve overlap technique. The engine was run under boosted conditions, in an operation regime where acceptable pressure rise rate (PRR) level is usually exceeded. Selected valve timing sweeps were carried out within a scope of the experiments to evaluate PRR reduction potential. The obtained results manifested superior combustion controllability. Late exhaust valve closing enabled reduction of the amount of internally re-circulated exhaust, which propagated to the main event combustion. From the intake side, two effects were observed, i.e. variability of the intake air aspiration and variability of the apparent compression ratio. Both phenomena were found to affect combustion timings and rates.

Schlüsselwörter

  • low temperature combustion
  • HCCI
  • valve actuation
  • combustion harshness
Uneingeschränkter Zugang

Friction Losses in a Linear Hydraulic Motor as a Result of the Influence of the Control Structure and Oil Viscosity

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 377 - 384

Zusammenfassung

Abstract

The problem of energy tests of hydraulic systems with hydraulic cylinders, seemingly simple displacement machines, is more complex than that of rotary hydraulic systems. The results of the researches provide an insight into the impact of external loads, required speed, structure of the power supply system, viscosity of hydraulic oil on friction loss, and the efficiency of cylinder drive. The hydraulic cylinder is the strongest structure in the system. Failure of the system is most likely due to failure of the pump supplying the cylinder. The high load of the pump is often caused by the very low energy efficiency of the cylinder, which, despite a relatively low external load, requires high inlet pressure due to large mechanical losses of friction between the piston and the cylinder and between the piston rod and gland. These losses depend on the type of seal used, its shape, the material it is made from, pre-clamp, and the operating parameters of the cylinder. Improperly sealed or assembled seals can cause energy losses of up to 25%. Due to the use of moving seals in the hydraulic cylinder, its energy behaviour is completely different compared to the energy behaviour of a rotary motor, which does not have any seals. The friction force connected with the work of the sealing joints and the mechanical efficiency of the cylinder are determined not only by the external load but also by the method of the applicable supply of the cylinder resulting from the throttling structure, and in particular the pressure level generated in the discharge chamber of the cylinder.

Schlüsselwörter

  • friction force
  • mechanical losses
  • energy efficiency
  • oil viscosity
  • hydrostatic drive
  • hydraulic cylinder
Uneingeschränkter Zugang

Laboratory Tests of Stand-Alone Hydraulic Piezo-Valve

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 385 - 391

Zusammenfassung

Abstract

Flow control inside the aviation landing gear shock absorbers is nowadays performed by fixed orifices or by the half-active spring based valves located inside of the device. All of the mentioned solutions are optimized on limited, mostly to one, landing scenarios due to their non-adjustable nature (even spring based valves are treated as passive due to their lack of actual real-time controllability). The easiest way of full hydraulic fluid flow control is to mount in its way a valve, which is able to seamlessly open and close causing the flow to change in wide range. Unfortunately, most of the used solutions are too large or not fast enough to fit the shock absorber requirements. The most promising way is to design tailor-made valve based on a piezo crystal actuator, which is most suitable due to its size and speed. Such a design has been made and tested by the engineers of the Institute of Aviation in Warsaw in Landing Gear Laboratory. In this article, the author describes test campaign of the hydraulic piezo-valve. Several tests have been made in order to assess the design correctness and to determine the basic parameters of the valve. Achieved results, presented in this article, show the full functionality of the solution in laboratory tests according to the design assumptions [8].

Schlüsselwörter

  • laboratory testing
  • hydraulic valve
  • flow control
  • piezo crystal
Uneingeschränkter Zugang

Evaluation of Interior Air Quality in Terms of Volatile Organic Compounds Emission Inside a New Passenger Car Cabin Depending on the Temperature

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 393 - 398

Zusammenfassung

Abstract

The new passenger car, BMW 225 XE was tested. The results of measurements of concentration of VOCs carried out inside the car cabin depending on the temperature were presented. The investigation was carried out in a special climatic chamber isolated from external factors such as outside air pollutants and weather conditions. The following temperature values have been set: 17ºC, 20ºC, 35ºC and 50ºC. The samples were located inside and outside of the vehicle’s cabin. As expected, the concentrations of each compound increased with increasing temperature (volatility of VOCs increases with the temperature). Values of concentrations obtained in the measurements have been compared with the values of highest acceptable concentration specified in polish law. The article describes the investigation, which was provided in a special climatic chamber. The chamber was isolated from external weather conditions and pollutants. Before each sampling interior of car cabin was ventilated to remove all pollutants from inside. Concentrations of BTX measured in different temperatures were converted to temperature of 20ºC.

Schlüsselwörter

  • vehicles
  • road transport
  • materials
  • VOCs
  • air pollution
  • car cabin
Uneingeschränkter Zugang

Strain Gauge Measuring Plate for Dynamic Tests

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 399 - 404

Zusammenfassung

Abstract

In dynamic tests, especially landing gears, it is necessary to measure and record load levels. In this article, authors present measurement methods used in the landing gear tests on the 10-Ton Drop Test Machine, which is capable of simulating conditions similar to real landing in landing energy dissipation tests. Possible test objects include dampers, shock absorbers, and crash structures and devices. In described case load measurement can be done by several methods where one of them is strain-gauge plate based load measurement. This type of measurement is weighting system under the test object where all forces acting on it are measured. Strain gauge plate is usually tailor-made measurement system, which is composed out of mechanical device (plate itself) equipped with strain gauge force sensors, strain gauge amplification system and recording system. In addition, differences between static and dynamic measurements are described as well as influence of dynamic test conditions on strain gauges behaviour. In the article, authors describe general layout of the system, advantages and disadvantages of the test stand and problems that may appear during measuring. Authors also emphasize how the accuracy of the design affects to the quality of measurement. At the end of the article, advantages and disadvantages of the test stand and problems that may appear during measuring are described.

Schlüsselwörter

  • dynamic tests
  • strain gauges
  • measuring plate
  • test stand
Uneingeschränkter Zugang

The Freight Transport Effectiveness Assessment in the Aspect of the Use of Environmentally Friendly Vehicles

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 405 - 414

Zusammenfassung

Abstract

The freight transport combines the issue of supply services organization for various types of entities, including large shopping centres, stores of various industries, restaurants, work and leisure places, small-scale outlets, or municipal waste shipments. Due to the location of customers, transport services encounter many difficulties related to infrastructural constraints and increased traffic. This adversely affects the safety and obstructions in traffic and air pollution and thus is a disturbing factor for the lives of inhabitants. There is also a growing problem of the smog in large cities (in Poland, for example, Warsaw or Cracow). Traffic safety, minimization of congestion, and minimization of environmental pollution by transport activities are of particular importance in the development of freight traffic organization plans. In connection with the above, in recent years, the use of Environmentally Friendly Vehicles (EFV) in various spheres of human activity has been dynamically developing, and this concerns the cargo transport. Currently, vehicle manufacturers are providing an increasing number of delivery vehicles and trucks. On the other hand, entrepreneurs planning to implement pro-environmental solutions face a decision problem related to the efficiency of a transport system based on the use of EFV as well as the economic validity of implementing this type of innovation. In connection with the above, in this article, the problem of the impact of transport on the environment and the use of EFV in the freight transport was analysed. The main issues related to the functioning of the transport system and its negative impact on the environment has been presented. Environmental friendly vehicles and their parameters have been characterized. The main decision problems in organizing the transport system, also in the context of the use of EFV, have been identified and analysed. Finally, an example of a model for assessing the efficiency of a transport system with an emphasis on its impact on the environment was presented. The article was concluded with the summary of considerations and the proposal for further work.

Schlüsselwörter

  • freight transport
  • external costs
  • Environmentally Friendly Vehicles
  • EFV
  • Multicriteria Decision Analysis
  • transport system effectiveness
Uneingeschränkter Zugang

Vibrodiagnostic of Welded Thin-Walled Plates with the Usage of Laser Sensors in Network Infrastructure

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 415 - 419

Zusammenfassung

Abstract

The article presents a non-destructive welded joints assessment (vibrodiagnostics) method, in which, with the use of the Internet, computer networking technologies and laser displacement sensors, the quality of welded steel plates may be monitored. The article also describes the possibilities of analysis of received vibrodiagnostics data on the base of diagnostic parameters analysed in function of time and frequency. The method described in the article allows remotely registering, analysing and diagnosing mechanical systems using vibrodiagnostics and information technologies. Modern, computerized methods exhibit efficiency and reliability of results – they are currently the best measuring tools that can be used in automatic monitoring (structural health monitoring - SHM) of marine structures. It is essential to make objective assessment of the results by NDT users, which is tightly connected with the expertise of norms and regulations of NDT. It may be helpful in this respect to monitor responses from a few sensors, arranged in a few measuring points. NDT results quite often trigger further analysis of durability of an object. The NDT of welded joints method as presented in the article allows remotely and in an IT-aided way analysing and diagnosing mechanical systems with the use of vibrodiagnostics method.

Schlüsselwörter

  • non-destructive testing
  • laser displacement sensors
  • NDT
  • vibrodiagnostic
  • Ethernet
  • LAN
Uneingeschränkter Zugang

Thermodynamic Analysis of Combustion Events in The Natural Gas Fuelled SI Engine With VVT

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 421 - 427

Zusammenfassung

Abstract

The main aim of the research was to investigate influence of overlap of the natural gas fuelled spark ignited engine on the following parameters: Indicated Mean Effective Pressure (IMEP), heat rate release including combustion phases (ignition lag, main combustion phase). The content of the study includes results from processing in-cylinder pressure measurements, heat release rate analysis, combustion phases, and finally the conclusions. The tests were carried out on the test bed including the single cylinder research engine with a displacement volume of 550 cm3. The engine was equipped with independent cam phasors for both intake and exhaust valves, but for this investigation, the exhaust valve timing was fixed (the exhaust cam centre line was fixed at -95 crank angle (CA) deg before Top Dead Centre) and intake valve timing was changed (the intake cam centre line was varied from 90 to 150 CA deg after Top Dead Centre). The overlap was changed in the range from 85 to 25 CA deg. 8 tests series were performed, each singular series consisted of 300 consecutive engine combustion cycles. As observed, by varying the valve overlap it contributes to significant change in the peak combustion pressure, peak of heat release rate, and combustion phases. Summing up, variable valve timing affects compression and expansion strokes by changing polytropic indexes due to various amounts of exhaust residuals trapped in the cylinder. It affects not only engine volumetric efficiency but also the heat release rate and IMEP, so it does engine performance. Thus, variable valve timing can be considered as valuable tool that can be applied to the natural gas fuelled internal combustion engine.

Schlüsselwörter

  • internal combustion engine
  • variable valve timing
  • heat release rate
  • IMEP
  • combustion phases
Uneingeschränkter Zugang

CFD Tests of the Exhaust System of a Sports Motorcycle

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 429 - 436

Zusammenfassung

Abstract

The content of this article describes the area of the operation of speedway racing motorcycles, it reflects the specific use, and thus, the special requirements placed on the internal combustion engines used there. Then, a research tool is presented in the form of Computational Fluid Dynamics methods. The article presents basic equations as a base for software, and emphasizes the essence and necessity of adequate selection of turbulence models. Presentation of the work tool is crowned with a brief description of the application in the form of Ansys numerical analysis software and a specific place and possibilities of its application. The practical part describes the work carried out during the tests of a GM 500 type combustion engine and attempts to compare two types of exhaust systems whose advantages and disadvantages in analytical calculations are difficult to determine, whereas CFD tests accurately represent pressure fields, velocities and the most important parameter in the form of resistance of the exhaust system. The article is crowned with the results of tests enabling determination and selection of the exhaust system with lower flow resistance and recommendations adjusting the exhaust system to a specific engine.

Schlüsselwörter

  • CFD
  • speedway
  • spark ignition engine
Uneingeschränkter Zugang

Planning and Building 100% Renewable Energy Infrastructure with the Technologies of the Future

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 437 - 445

Zusammenfassung

Abstract

When and why humanity faced the Energy Problem, it is a question. What was the problem? How are we trying to handle it since the beginning? Do we have enough resources of renewable energy? Which technologies are mature enough to contribute and take part in the solution? Are they available in the market with compatible prices? What is the role of storage for dealing with the intermittent nature of renewable energy resources? Why do we need to build, operate, integrate and manage energy efficiency, storage and renewable energy in harmony with nature by smart grids in sustainable cities of the future? Is transition to 100% Renewable Energy the solution? If so what else is required to reach this target? What are we going to do with the existing system? Which methodologies and techniques we need to use to realize this transition with minimum costs and externalities? How are we going to justify this transition? Is it only a technology problem? What parameters we need to consider when we are trying to live in harmony with nature? How are we going to readapt human beings to be satisfied with minimum ecological footprint societies? Can human beings build democratic societies where energy efficiency and 100% renewable energy is respected and beneficial for each individual of the communities? Transition to 100% renewables requires planning the future with the information of the future. For reaching this target we need to carry on a multidisciplinary approach to understand and take into consideration the basic constraints and requirements of the living space we are sharing all together in the atmosphere. How to Speed-up the Global Transition to 100% Renewable Energy?

Schlüsselwörter

  • energy
  • efficiency
  • transition to 100% renewable energy
  • energy storage
  • smart grids
  • planning future
  • future technologies
Uneingeschränkter Zugang

Innovative Composite Gyroplane Rotor Blades – Fatigue Tests

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 448 - 453

Zusammenfassung

Abstract

The paper presents test bench method for verifying the fatigue life of the rotor blades, working in operating conditions in a position steady flight (autorotation), on the aviation construction called the gyroplane. One of the critical elements of this design is the main rotor, which in its modern versions takes the form of advanced composite structures subjected to loads in flight complex variable, the nature of which differs from the well-known operating conditions of helicopter rotors. The article includes a description of the test object, which are composite rotor blades designed specifically to work in autorotation, the specificity of loads of autorotation rotor, and method of implementation of the gyroplane rotor work cycles in the test bench. The main aim of this research is to evaluate the sustainability of the composite blades under the gyroplane operating loads with the goal to allow the rotor to operate in the air. The tests were carried out for 100 hours of gyroplane flight at loads do not exceed the maximum operating loads, and for several hours under a load higher than operating. During test for the evaluation of composite structure, the infrared camera with dedicated software IRNDT was used. The reached showed structural integrity in critical mounting section of the blade.

Schlüsselwörter

  • rotor blades
  • fatigue tests
  • NDT
  • composite
Uneingeschränkter Zugang

Numerical Analysis of Residual Stress Distribution in Riveted Lap Joint Under Tension

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 455 - 462

Zusammenfassung

Abstract

Riveted joints are a common location of fatigue cracks in aircraft metal structures. Fatigue life of such joints as well as a place of cracks nucleation is strongly influence by a stress distribution in sheets, which is a result of residual stresses (mainly after riveting) and stresses induced by external loads. Stress distribution in two-row lap joint was investigated with the use of Finite Element Method. The joint consist of two 1.5 mm sheets and two protruding rivets with diameter equal to 4 mm, made of 2024 T3 (sheets) and 2117 T4 (rivets) aluminium alloys. The simulations covered a riveting process and tensile stages. The 3D models of joint with the universal rivets and with the brazier, rivets with a compensator were prepared. Elastoplastic material properties as well as geometric nonlinearity and contact phenomena were included. The results of simulations show that the residual stress distribution after release of tensile loading varies significantly from the distribution after riveting only. This fact should therefore be taken into account in a fatigue life estimation of such joints performed based on a FE calculation. The paper presents also the influence of the analysed rivet geometry on the stress distribution at the sheets faying surfaces.

Schlüsselwörter

  • joint
  • rivet
  • fatigue
  • residual stress
  • finite element
Uneingeschränkter Zugang

The Influence of Selected Adhesive Properties and the Manner of Surface Preparation upon Impact Strength of Block Adhesive Joints

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 463 - 469

Zusammenfassung

Abstract

The research described in this article is part of investigating impact strength in block adhesive joints. The authors checked experimentally the effect, on the test results, of the manner of surface preparation and compressive strength and Young’s modulus of an adhesive used to make the connection. The experimental testing was carried out with an impact pendulum tool, designed to examine adhesive joints. During such testing, the energy used to tear off the upper part of the specimen, that is the energy lost by the dropping device, is the measure of the impact strength of an adhesive connection. The elements of the samples were made with an aluminum alloy 2017A. In the investigations, the authors used non-normative samples whose upper element was a cylinder rather than a cuboid, as advised in the norm. The adhesive joints were made using epoxy adhesive Loctite, named EA 3421, or an adhesive composition Epidian 57 with Z1 hardener. The glued elements were prepared by treating the surfaces for bonding by means of the stream-abrasive processing. The abrasive mediums were three types of materials of different gradation. In addition, two series of samples were prepared using roughening by sandpaper. For control samples, the authors made joints, in which the surfaces for bonding became degreased merely by petroleum ether.

The results of the experimental studies indicate that the impact strength of adhesive joints is dependent on the manner of preparation of the bonded elements as well as on the longitudinal modulus of elasticity of the adhesive, which was used to make the connection.

Schlüsselwörter

  • adhesive joint
  • impact strength
  • adhesive properties
Uneingeschränkter Zugang

The Methods of Quality Assessment of the Tracked Suspensions of the Combat Vehicles

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 471 - 478

Zusammenfassung

Abstract

The extortions that result in the vibrations of a hull of the combat vehicle have an impact on the tracked combat vehicle during the off-road driving. They may have a negative impact on the crew, internal equipment, shooting accuracy. A level of the hull loads depends on quality of the suspension system, which main responsibility consists in minimising an amplitude of the vibrations. Therefore, it is necessary both to improve a structure of the suspension system, and its components, as well as their optimisation.

The tests of the driving smoothness of the vehicle and quality of the suspension elements can be realised both within a frame of the model tests and while driving in the real conditions. The assessment criteria of the driving smoothness are directly related to the negative influence of the vibrations to the human body. The suspension quality should be assumed both upon an execution of the vehicle prototype, and during the design or modernisation phase. It results both in reducing the time, and minimisation of the costs and risk related to the structure development. The model tests enable to evaluate the driving smoothness and comfort prior to an execution of the prototype. The tests on the test tracks in the final phase of the development are carried out in order to evaluate the driving smoothness.

Schlüsselwörter

  • tracked combat vehicle
  • suspension
  • driving smoothness
  • test track
Uneingeschränkter Zugang

The Application of Ant Algorithm in the Assignment Problem of Aircrafts to Stops Points on the Apron

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 479 - 487

Zusammenfassung

Abstract

The article refers to the problem of assigning the aircrafts to stops points on the apron. The aim of this paper is to develop the algorithm, which will be used to this assignment. The assignment problem of aircrafts to stops points is the complex decision problems, which refer to the problems of designating the minimal path in the graph. The assignment model was described, i.e. decision variables, constraints and the criterion function. Decision variables take the binary form and determine the connections between the elements of infrastructure of the apron, i.e. touchdown points, intermediate points and stop points. Constraints take into account the number of aircrafts in the given period, the number of unoccupied stop points. The criterion function determines the minimum driving time of the aircraft on the apron. In order to designate the routes in international transport the heuristic algorithm, i.e. ant algorithm was developed. The steps of building this algorithm were presented. This algorithm was verified in the C# programming language. The results generating by the presented algorithm were compared with the results generating by the random algorithm.

Schlüsselwörter

  • air transportation
  • air traffic control
  • aircraft operations
  • airport
Uneingeschränkter Zugang

The Car Fleet Management Model with Including Expectations of the Users

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 489 - 500

Zusammenfassung

Abstract

The paper presents a certain approach to fleet management in the company, taking into account the mobility of employees and the selection of vehicles for tasks. The main objective is to indicate the factors that significantly affect the proper selection of vehicles for the task, as well as concurrently meeting recipients' needs. The general model for fleet management was presented, taking into account not only the mobility of employees but also the method of obtaining funds for the replacement of greener cars. The current approach is based on the car purchase model in the form of credit, low-purchase leasing, and supervision over the use process and operating costs by the company's internal resources. The problem solved in the article concerns the analysis of entrusting fleet management to specialized Car Fleet Management (CFM) companies. It was pointed out that in this calculation model, CFM companies have to take into account many variables related to vehicle selection and mobility of employees in order to perform tasks. In this article, particular attention has been paid to the areas that CFM analyses when choosing a vehicle for a given company.

Schlüsselwörter

  • Car Fleet Management
  • assignment of vehicles to tasks
  • decision-making model of fleet management
Uneingeschränkter Zugang

Advantages of Compressor Downstream Air Partial Bleed and Supplying It Downstream of the Turbine in a Turbojet Engine

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 501 - 508

Zusammenfassung

Abstract

The research article discusses the advantages of using compressor downstream air partial bleed and supplying it downstream of the turbine, which was applied in a prototype of a “bypass” turbojet engine. The objective of such a turbo engine structural solution was discussed along with its elements and principle of operation. Further part of the article determines the impact of such partial air bleed on the value of achieved basic operating parameters of the engine, i.e., unit thrust and unit power consumption. The presented attempt to compare these parameters with the parameters achieved for a turbojet, single flow engine is very important; in the first case without air bleed, and in the second, with air bleed to the environment. Further sections of the article compared these parameters relative to a turbojet, turbofan engine with a jet mixer. Such comparisons enabled to determine the actual benefits of using compressor downstream air partial bleed and supplying it downstream of the turbine, which may constitute an intermediate solution between single flow turbine engines and turbo fan engines. Wide possibilities for the application of such structural solutions were shown, which was summarised in the conclusions.

Schlüsselwörter

  • aviation engine operating parameters
  • jet engine designs
  • aviation engine air bleed
Uneingeschränkter Zugang

Impact of Work of Turbine Adaptive Engines for the Natural Environment

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 509 - 516

Zusammenfassung

Abstract

The article describes the problem of the operation of turbine jet, adaptive engine work on the natural environment. In particular, the analysis of noise generated by turbine jet engines has been made. It points out possible directions of noise decrease with particular emphasis upon structural changes within the engines, the task of which is to reduce the noise mission. The example of the modernization is based upon the “bypass” type of one-flow turbine jet engine. The essay contains theoretical basis of calculation of the noise emission level and the results, which graphically indicate a relative level of noise of this type of engine depending upon the amount of discharged air and the diameter of the discharge nozzle and the radius, upon the basis of which the noise level is determined. This work also includes a comparison of the relative noise level of this type of engine with regard to one-flow turbine engine equipped with the function of air discharge to the environment and with regard to two-flow turbine jet engine equipped with air stream flow mixing device. The use of low-emission combustion chambers in the “bypass” turbine engine was indicated. This allowed addressing the problem of emissions of toxic exhaust components by this type of aircraft engines. At the same time, the dependence of this emission related to the mass of fuel used on the engine's thrust range was indicated. The article was concluded with a short summary.

Schlüsselwörter

  • noise of aircraft engines
  • the environmental impact of a jet engine turbine
  • emission of toxic compounds from aircraft engines
  • turbine jet engine
Uneingeschränkter Zugang

Selected Problems of Diagnosing Toothed Gears in the Aspect of Developing HUMS System

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 517 - 524

Zusammenfassung

Abstract

A diagnostic FDM-A method, based on the measurement of modulation of constituent frequency of direct current (DC) generator pulsation as well as FAM-C method, established on the measurement of frequency modulation of alternating current (AC) generator, were developed in the Air Force Institute of Technology [3, 9-10]. The essence of their accuracy lies in “natural” synchronizing of sampling with angular speed of the observed kinematic pair – if the dynamic processes of the observed object accelerate, the sampling becomes faster too [9-10]. At the same time, around the “synchronization points”, due to the clearance in the power transmission there is a certain natural oscillation between the observed kinematic pair and generator’s rotor − vibrations are created. These vibrations are called jitter [9, 23] and they constitute an additional supplement to this method, because they provide more information on resolution and accuracy. Moreover, the abovementioned method enables to define the level of subassembly abrasive wear and its location in the time of normal operation of the powerplant [9-10]. This method allows also detecting resonances of elements on the basis of observation of shape and relative position of characteristic sets, which i.e. enable to calculate the mechanical quality factor of kinematic pair − it is possible to establish the operation time of kinematic pair until entering the resonance degradation. Other numerous parameters associated with the assembly of power unit rotor were also outlined: rotor skew angle, level of frictional wear of bearing cage − lack of contact of bearing components, bearing assembly ovalisation.

Schlüsselwörter

  • aviation
  • alternator
  • frequency modulation
  • helicopter gearbox
  • bearing wear
  • gear wear
  • Health and Usage Monitoring System (HUMS)
  • power transmission
  • characteristic pattern
Uneingeschränkter Zugang

The Design and Simulation of an Automated De-Icing Control System in the Aircraft Diamond DA42

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 525 - 532

Zusammenfassung

Abstract

The article discusses the automatic control system of the Diamond DA42 aircraft anti-icing system. In the analysis of the issue of icing, four parameters were taken into account: air temperature, cloud humidity, temperature of the aircraft and precipitation. On the basis of the initial parameters, the authors determined the icing intensity, which is likely to occur on the aircraft skin. By automating the activities related to the activation of the de-icing system, it is possible to significantly relieve the pilot and increase the safety of air operations, particularly in conditions, which are conducive to the formation of icing. The authors performed a thirty-minute electronic simulation of the flight in real atmospheric conditions. The article discusses the obtained results of the simulation. Designed system uses fuzzy logic. The system inputs and output were determined and fuzzy expert inference system was developed in MATLAB software and Fuzzy Logic Toolbox. The proper system work was verified with use of MATLAB/Simulink software. Use of that kind of systems can significantly relieve the pilot and increase the safety of air operations, particularly in conditions, which are conducive to the formation of icing.

Schlüsselwörter

  • anti-icing installation
  • icing
  • Diamond DA42
  • aircraft
  • general aviation
  • MATLAB
Uneingeschränkter Zugang

Technical and Organizational and Legal Conditions Relating to the Power Supply of a Railway Vehicle Equipped with Automatic Train Control System

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 533 - 545

Zusammenfassung

Abstract

Railway transport is considered the most environmentally friendly. However, taking into account all factors, (including point pollution associated with the production of energy necessary for the movement of electric traction vehicles); this position is attractive, but a little less. Therefore, it is necessary to ensure that the amount of energy produced for railway transport is sufficient, but the lowest as possible. Creating new systems whose components for correct operation require a supply of electricity, they should be designed in such a way as to consume as little energy but meeting a series of standards. The aim of the article is to review selected requirements for the power supply of a railway vehicle equipped with automatic train control devices and identification of energy demand in the scope of supplying the rmCBTC on-board system, which is being developed by Rail-Mil Computers Company from Warsaw and the Faculty of Transport of the Warsaw University of Technology. The article presents an analysis of formal and legal requirements in the field of traction vehicles. Reference was made to the list of the Office of Rail Transport and the standards not included in it − PN-EN 50155, PN-EN 61000-6 and PN-EN 50125-2. Energy requirements in the field of traction vehicles equipped with an automatic train control system have been identified − e.g. voltage range of the onboard system, permissible decays, voltage dips, disturbances and environmental requirements. The energy requirements for the rmCBTC on-board system were also identified.

Schlüsselwörter

  • railway transport
  • automatic train control system
  • electricity
  • rmCBTC
  • power requirements
Uneingeschränkter Zugang

Evaluation of the Compliance of Aircraft Wing Flap with Use of the Fracture Mechanics

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 547 - 554

Zusammenfassung

Abstract

Research in the field of fracture mechanics and determination of material characteristics are used for practical purposes, such as the assessment of static and dynamic strength of structural components, analysis of their fatigue life or extending the life span of their operation. A structural component, considered to be safe from fatigue cracking point of view, was investigated and results were presented in this article. In particular, an analysis was made to determine the stress intensity factor for the cracked wing flap construction, based on static and fatigue tests, using the Irwin-Kies theory. The flap with a service crack was subjected to fatigue tests with a load similar to the one registered during flight measurements. The flap without a service crack was subjected to static tests, after cutting the cracks of specified lengths and shapes (similar to the service crack) in the skin of the flap. The article presents changing the length of the flap crack in subsequent load cycles, change in the maximum values of force and the crack opening displacement in subsequent load cycles, dependence of P-COD in the first and second stage of fatigue testing of the wing flap, dependence of the wing flap compliance on the length of the crack and experimentally determined dependence for wing flap. The occurrence of a flap crack up to approximately 230 mm does not cause a significant growth of the stress intensity factor.

Schlüsselwörter

  • airplane wing flap
  • crack growth
  • stress intensity factor
  • Irwin-Kies theory
Uneingeschränkter Zugang

Selected Aspects of Indoor Positioning Based on AIDC Elements in Warehouse Facilities

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 555 - 562

Zusammenfassung

Abstract

The article presents classification of automatic identification and data acquisition techniques (AIDC) as well as techniques for indoor positioning of objects supporting logistic processes, including especially warehousing processes. The use of presented solutions and the possibility of combining AIDC technics with indoor positioning systems to increase the efficiency of logistics processes in warehouses were discussed. This combination can make a tool supporting rational decision making for allocation of idling employees and vehicles to warehouse tasks and reducing empty runs on the base of position analyse. Then, the idea of using popular AIDC devices − mobile terminals with and without RFID scanners to track the position of employees was presented and discussed. Mobile terminals can provide information about position, which can be used for the allocation of tasks (the reverse functions of mobile terminals). Review of AIDC techniques in warehouses and industrial facilities, information flow in AIDC techniques, positioning techniques in a closed space, Resources positioning and the efficiency of the warehouse process, typical and new approaches to positioning resources in warehouse, the reverse function of mobile terminals are presented in the article.

Schlüsselwörter

  • AIDC
  • indoor positioning
  • warehousing
  • logistics
Uneingeschränkter Zugang

Engine Researches on the Influence of the Piston Ring Insert on Temperature Distribution in Piston

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 563 - 570

Zusammenfassung

Abstract

The article presents a method of piston temperature measurement on a running engine using electromagnetic induction for transferring measurement results from a moving measuring system placed in a piston to a stationary system attached to the engine crankcase and to measuring system located outside the engine. Selected test results that were carried out on a single-cylinder Diesel engine are presented. A system consisting of a thermistor and a secondary coil was mounted in the piston. The primary coil was mounted in the crankcase under the cylinder liner of the engine. Engine tests were aimed at determining the influence of the piston ring insert on the temperature distribution in the piston. Temperature measurements in the piston without the ring insert were carried out for comparison. In both cases, the pistons had the same geometrical dimensions. The tests were carried out in conditions of external characteristics (the maximum load as a function of engine speed) and load characteristics (load changes at constant engine speed). The test results in the form of the temperature difference between the temperature of piston top and the temperature under the top compression ring indicate that the ring insert is a barrier to the heat flow from the piston to the engine cooling system. In addition, the results of the piston temperature measurements during the step change of the engine speed and its load to the nominal value are presented.

Schlüsselwörter

  • combustion engine
  • engine piston
  • piston ring insert
  • electromagnetic induction
  • temperature measurement
  • thermistor
66 Artikel
Uneingeschränkter Zugang

Application of Drones in Protection of State Border

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 9 - 15

Zusammenfassung

Abstract

An unmanned aerial vehicle is a flying apparatus that does not require a crewmember on board to complete a task. Its piloting is done by means of indirect control. UAVs also have the ability to perform autonomous flight on a pre-programmed flight path. The purpose of the study was to use the unmanned aircraft “Fly Eye” by WB Electronic used by the Border Guard to patrol the state border in 103 TRA zone on the section of the Republic of Poland with the Kaliningrad District of the Russian Federation. The TRA zones constitute a specially designated area for the use of the Border Guard and the army, in order to carry out flights there beyond the scope of the pattern for training purposes and to patrol the state border. The article also contains information of the Border Guard formation and the characteristics of the unmanned aerial vehicle “FlyEye”. In order to ensure the safety of the UAV flight, the test was carried out in the TRA zone, which is used for special use for the Border Guard formation and the army.

Schlüsselwörter

  • Unmanned Aerial Vehicles
  • Flying Platform
  • Drone
  • Unmanned
  • UAV
  • Unmanned Aerial Vehicle
  • Fly Eye
  • Border Guard
  • Operator
Uneingeschränkter Zugang

The Role of Molecularly Ordered Structures in Energy Transport Enhancement During Combustion Process – A New Conception of a Reaction Mechanism of Fuel Components Oxidation

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 17 - 24

Zusammenfassung

Abstract

This article presents the results of investigations focused on the role of molecularly ordered structures (molecular clusters) on combustion process. The proposed new mechanism of the reactions initiation takes into account the role of molecular clusters in energy (heat and energy of electrons emitted by the surface of the walls of combustion chamber) conductivity regulation. Literature survey shows that molecular clusters created by aromatic hydrocarbons are responsible for particulate matter. The combustion process itself is not uniform in whole combustion chamber. Such diversity, caused mainly by heterogeneous thermal state of combustion chamber is recognized as significant reason to create various products of combustion including carbon oxides, carbon dioxides and nitrogen oxides. Jet fuel and its blends with n-butanol and biobutanol in concentration from 10 to 75 % (V/V) were subjected to laboratory tests. Such blends were also tested on the test rig with a miniature turbojet engine – MiniJETRig. Engine operating parameters and carbon oxide emission were measured. The relations between electrical conductivity and parameters of engine test (e.g. temperature in selected points in combustion chamber) were assessed. Engine tests were carried out according to specific profile of engine test, which models different engine operating modes. The results of experimental investigations, shown in the article, initially confirm the proposed mechanism of the oxidation reactions initiation during combustion process.

Schlüsselwörter

  • molecular clusters
  • turbojet engine
  • butanol
  • combustion process
  • carbon oxide emission
Uneingeschränkter Zugang

Database of Expert Diagnostic System in the Field of Turbine Blades Non-Destructive Testing

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 25 - 32

Zusammenfassung

Abstract

The article presents selected problems in the synthesis of the database of expert diagnostic system of gas turbine blades in the field of non-destructive testing. The source of data is optical methods and computed tomography methods. Optical tests can be carried out on the blades of the turbine built in the engine and after their disassembly. Optical tests provide diagnostic information in the form of an image of the blade surface. This makes it possible to identify damage based on changes in the attributes of the image of the blade surface. Computer tomography methods are applied on disassembled blades. Assessment of the technical condition of the blade is made on the basis of individual two-dimensional X-ray scans or on the basis of a three-dimensional image of the blade generated by the computer software from the set of X-ray scans taken during the full angle rotation. The computed tomography data set includes a small number of points on the timeline of operation; hence, the correlation of results with optical methods is difficult. Integration of diagnostic data from two or more sources into one expert system requires standardization of data. One possible approach is the use of multi-valued encoding of 2D and 3D image attributes. In this way a multi-valued diagnostic model of the blade is obtained, which can be processed by information theory methods to optimize the set of attributes.

Schlüsselwörter

  • gas turbine
  • blade
  • diagnostics
  • technical condition
  • expert system
  • database
Uneingeschränkter Zugang

Methods of Modern Aircraft Aeroelastic Analyses in the Institute of Aviation

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 33 - 42

Zusammenfassung

Abstract

The aeroelastic phenomena analysis methods used in the Institute of Aviation for aircraft, excluding helicopters, are presented in the article. In industrial practice, a typical approach to those analyses is a linear approach and flutter computation in the frequency domain based on normal modes, including rigid body modes and control system modes. They are determined by means of the finite element method (FEM) model of structure or a result of ground vibration test (GVT). In the GVT case, relatively great vibration amplitudes are applied for a good examination of a not truly linear structure. Instead or apart from the measure of generalized masses, a very theoretical model is used for mode shapes cross orthogonality inspection and improvement. The computed or measured normal mode sets are the basis for flutter analysis by means of several tools and methods, like MSC.Nastran and ZONA commercial software as well as our own low-cost software named JG2 for the flutter analysis of low speed aeroplanes and for a preliminary analyses of other aircraft. The differences between the methods lie in determining normal mode set, unsteady aerodynamic model, flutter equation formulation, time of analysis, costs, etc. Examples with results comparison obtained by means of distinguished methods are presented. Some works in the field of aeroelastic analysis with nonlinear unsteady aerodynamic in the time domain using Tau-code and ANSYS Fluent software were also performed. Aeroelastic properties of deformed structures, like a sailplane with deflected wings, can be also analysed. The simplest way of this analysis is the semi-linear approach in which the deflections modify the aircraft geometry for normal modes determination.

Schlüsselwörter

  • flutter
  • normal modes
  • ground vibration test
  • unsteady aerodynamic models
Uneingeschränkter Zugang

Effectiveness of the Active Pneumatic Suspension of the Operator’s Seat of the Mobile Machine in Depend of the Vibration Reduction Strategies

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 43 - 48

Zusammenfassung

Abstract

Low speeds of heavy mobile machines combined with large inertia result in the excitation of low frequency vibrations. Dissipation of vibration energy in the case of unsprung machines is performed only through tires, which slightly reduces the intensity of vibrations. Effective reduction of vibrations of mobile machines is possible only with active or semi-active methods. In unsprung mobile machines, on the way of propagation of vibrations between the source of vibrations and the protected object (machine operator), are vibroisolation systems located. These are most often controlled seat suspensions. In the case of the active suspensions, it is necessary to provide external energy, e.g. in the form of compressed air. The compressed air has the advantage that it is generally available in working machines as the working fluid and has its environmentally friendly properties (leaks do not contaminate the environment). This article is the result of the continuation of work on active methods of vibro-activity lowering in mobile machines, which resulted in, among others, elaboration of simulation model of the active operator’s seat suspension with controlled pneumatic actuator and its experimental identification. In particular, it was verifying the effectiveness of the adopted solution made the identification the friction model and thermodynamic phenomena in the controlled pneumatic cylinder. The aim of this work is parametric optimization of the suspension system and searching for the optimal control strategy. Experimental tests were carried out under conditions of harmonic excitations, coming from the electromechanical vibration exciter with controllable pitch and frequency. Data acquisition system and control circuit of the proportional directional control valve, supplying compressed air to the actuator were implemented using MATLAB-Simulink Real-Time software.

Schlüsselwörter

  • unsprung mobile machines
  • active vibration reduction
  • controlled suspension seats
  • pneumatic actuator
Uneingeschränkter Zugang

Experimental Study and Neural Network Modelling of Aerodynamic and Dynamic Characteristics of Flapping Wings Micro Aerial Vehicle

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 49 - 57

Zusammenfassung

Abstract

The article is close connected with building flying object, that fly like an insect (entomopter). Present work concerns on concept of aerodynamic model using artificial neural networks. Model is used in simulations of flight of entomopter. Aerodynamic model based on experimental data. Necessary data are taken from experiment performed in water tunnel on entomopter model. For this case dynamic test are required. Measurements are ducted during sinusoidal motion of whole model. Modelled object is dipterous. Each wing can perform various spherical motions (wing is rotated around point). The motion of the wing in this case was two-dimensional; it was rotated around two axis. As a model, specially trained neural network is used. For training are used data from measurement. Presented in this article approach is based on artificial neural networks. In this article, innovative concept of model, describing unsteady aerodynamics of entomopter was proposed. It was shown that it could be easily implemented as mathematical model. Unsteady effects related to many state variables can be easily captured. Model can be easily adopted to predict different states of flight by networks training on appropriate data. Test has to reproduce real conditions as close, as it is possible. In reality, it is challenging to design test that will reproduce similar motion.

Schlüsselwörter

  • entomopter
  • flapping wings aerodynamic neural network modelling
Uneingeschränkter Zugang

Processing of Long Lasting Signals of Torsional Vibrations Measured Using Incremental Encoders

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 59 - 65

Zusammenfassung

Abstract

The article describes processing method of a signal, coming from torsional deflections of an internal combustion piston engine’s crankshaft, registered using two optical encoders ETNP-10. Standard measurement and recording set ETNP-10 enables recording of Instantaneous Angular Speed values encompassing 10 revolutions of the crankshaft, what is equal to 5 cycles of four-stroke engine. That time duration is sufficient for analysis of changes of angular speed caused by, for example, malfunction of fuel injection valve, but is insufficient in case of observation characterized by low frequency changes with period of fluctuations, lower than 0.8 sec. Short time for recording makes impossible following of instantaneous angular speed deviations caused by magnitude modulation of engine’s load value. In the article is presented an algorithm written in MATLAB environment, which allows processing of the data recorded using the recorder DAS 1600 Sefram. The recorded this way signals have around 26 seconds' duration of engine work. Data acquired from two encoders mounted at opposite sides of the shaft, in form of square magnitude signals are transformed into instantaneous speed and subsequently to instantaneous angular shift, what is basis for torsions calculation. In the article is also presented method of elimination of systematic error due to assumed method of averaging. Finally, some examples of results of torsional deflection measurement and analysis are presented.

Schlüsselwörter

  • diagnostics
  • diesel engine
  • torsional vibrations
  • torque and angular speed
Uneingeschränkter Zugang

Tooling Development for Thermoplastic Composites Thermoforming Process Based on FEM Analysis – a Rib Case Study

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 67 - 74

Zusammenfassung

Abstract

Remarkable characteristics of high temperature thermoplastic (HTP) matrix used in composite materials reinforced with continuous fibres causes growing application in composite industry. Because of high processing temperature of some semi, crystalline matrix there is limited number of technologies that can be used for part manufacturing. Press forming is an example of technology that allows manufacturing high quality complex parts made of HTP reinforced fibres composite. In order to manufacture part with acceptable quality and mechanical properties, uniform pressure distribution during the process is required.

In this article, tooling design process focused on uniform pressure distribution for manufacturing of supporting rib was presented. In order to satisfy this requirement, the rubber stamp was proposed as a tool for manufacturing. Typical press forming process defects were identified and the requirements for rubber stamp were described. It was assumed that the forming process has to begin at one point on mould surface and sequentially continue in all directions. For stamp material, the two components additive silicone was selected. The hardness of the silicone was equal 40 Shore A. The rubber mechanical properties was determined through the additional tests and used for stamp designing. The tooling was designed using FEM software ABAQUS 6.12.

The sequence of stamp shape designing and optimization in order to meet the stamp requirements was presented. At the end the FEM rubber stamp designing recommendation were presented.

Schlüsselwörter

  • rubber thermoforming
  • rubber press forming
  • thermoplastic composite
Uneingeschränkter Zugang

The Influence of the Geometry of the Cutting Edge and Machining Parameters of Duplex Cast Steel After Turning

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 75 - 81

Zusammenfassung

Abstract

The development and research activity is connected to the production of newer and more functional products. Innovative processes are being developed and applied; services and projects are delivered. Products are work items that should be initially designed, then manufactured and finally sold and utilized. Examples of products may be airplanes, ships, cars, machine tools, gears, crankshafts, drive shaft, tubes as well as gasoline, electricity and gas, etc. The product has to meet the expectations of the future use. It is characterized by a set of functional features. In the case of machines and their capabilities and performance, for example, durability, reliability, resulting from the characteristics represented by the structural units forming the structure. The formation of the desired features of the surface layer in the technological process is an important problem due to the ability of the elements of kinematic pairs to fulfil the function as long as possible foreseen for them. The article presents results of experimental studies of turning cast steel grade GX2CrNiMoCuN25-6-3-3. The aim of the research was to determine the geometry of the cutting edge and the technological parameters of cutting that are conducive to obtaining the roughness in the field of very accurate machining. It can achieve the appropriate technological quality of the workpiece surface. After these experimental studies was determined that there is a reduction roughness using suitable inserts. Turning was made for the duplex cast steel. The technological parameters of machining process were used: feed rate f = 0.1-0.2 mm/rev, depth of cut ap = 0.5 mm, cutting speed vc = 50-100 m/min. Turning was made using universal lathe CDS 500x1000 equipped with CCMT carbide tipped inserts.

Schlüsselwörter

  • turning
  • finishing
  • forming surface layer
  • surface roughness reduction
  • duplex cast steel
Uneingeschränkter Zugang

Experimental Research of the Material Filtration Characteristics with Nanofibers Addition

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 83 - 94

Zusammenfassung

Abstract

Nanofiber properties and the possibilities of their application in industry, including car air intake filtration materials production for vehicle engines are discussed. The attention is paid to the standard filtration materials low efficiency in the range of dust grains below 5 μm. Filtration materials properties with nanofibers addition are presented. Filter paper test conditions and methodology at the station with particle counter were developed. Filtration efficiency characteristics, and accuracy studies as well as filtration materials pressure drop differing in structure were made: standard paper, and materials with nanofibers addition. These are commonly used filter materials for car air intake systems production. Filtration materials with nanofibers addition test results show significantly higher efficiency values, and efficiency for dust grains below 5 μm in comparison with standard filter paper. It was found that there are 16 μm dust grains in the airflow behind the cellulose insert, which may be the reason for the accelerated wear of the engine’s “piston-cylinder” association. Lower dust mass loading km values of filtration materials with nanofibers addition in relation to standard filter papers were observed.

Schlüsselwörter

  • engine
  • air filter
  • filtration materials
  • nanofiber filter media
  • filtration efficiency
  • filtration performance
  • pressure drop
  • dust mass loading
Uneingeschränkter Zugang

Electromobility and Hydrogenization of the Motor Transport in Poland Now and in the Future

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 95 - 101

Zusammenfassung

Abstract

The article analyses activities within the world, EU and Poland in aspect electromobility and hydrogenization now and in the future. Will be presented estimates cars park of global hybrid (HEV), hybrid plug-in (PHEV) and fully electric (BEV). Changes in production volumes and number of registered types of vehicles as abovementioned are presented in a breakdown into world.

The overall number of HEVs produced thus far is estimated at approx. 12.5 million and over 1.3 million in Europe. There are roughly 38 thousand HEVs registered in Poland. There were about 800.000 hybrid plug-in vehicles registered in the world in 2016. Of 3.2 million electric plug-in vehicles and BEVs used in the world in 2017 more than 1.2 million were used in China, approx. 750 thousand in the USA, 850 thousand in Europe, including c.a. 650 thousand in the EU countries.

Yet, electric plug-in vehicles (BEVs and PHEVs) globally accounted for just 0.3% of the worldwide fleet of passenger cars in 2017. The article also addresses the development of the electric vehicles market and the annual new vehicle registrations.

The existing situation in the field of hydrogenization motor transport in the world, in the EU and in Poland will also be analysed. This will be analysed in terms of the number of hydrogen vehicles and hydrogen refuelling stations.

Schlüsselwörter

  • road transport
  • hydrogenization
  • combustion engines
  • electromobility
  • environmental protection
Uneingeschränkter Zugang

Advantages of Using Hybrid Vehicles Based on Empirical Studies on the Chassis Dynamometer in the WLTC Test

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 103 - 109

Zusammenfassung

Abstract

Vehicles powered in alternative ways have an increasing share in the car market. Their use is becoming more and more justified considering the ever more stringent standards for the emission of harmful substances from the exhaust systems of internal combustion engines and the introduction of restrictions on vehicle traffic in city centres. The possibility of using in the propulsion systems only an electric motor or its simultaneous use with the internal combustion engine enables a significant reduction of emission of harmful exhaust gas pollutants. This applies in particular to urban areas, where there are numerous exceedances of acceptable air quality standards. This problem is most noticeable in larger cities in Poland, where there is a lot of traffic. It is therefore legitimate to promote alternative vehicles powered in alternative ways. Their dual power system gives the opportunity to significantly reduce the emission of harmful substances. Therefore, the article presents own research, carried out on a chassis dynamometer, using two passenger cars, one with a spark-ignition combustion engine and the second with a hybrid drive system containing a spark-ignition engine and an electric motor (system without the possibility of recharging batteries from external sources). Vehicles were characterized by similar mass and the same displacement volumes of internal combustion engines. The results of the tests made it possible to compare cars in terms of exhaust emissions. For testing purposes, a chassis dynamometer was used, on which the WLTC homologation cycle was repeatedly reproduced. This is a new driving cycle, which replaces the NEDC cycle used so far in the type approval procedure in the European Union.

Schlüsselwörter

  • road transport
  • combustion engines
  • hybrid powertrains
  • air pollution
  • exhausts emissions
Uneingeschränkter Zugang

Selected Problems to Support Decision Making in a Simulation Environment

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 111 - 117

Zusammenfassung

Abstract

The article is devoted to the problem of decision support in a simulation environment prepared for the air traffic control service. The limitations resulting from the functionality of the airport have been presented. In addition, the “integration” problems resulting from the movement of aircraft on the apron have been presented. The article outlines optimization problems such as minimizing the total taxiing time, taking into account the waiting time for the start of the runway, minimizing the time elapsed from the first taxiing to the end of taxiing by the last aircraft or multi-faceted functions, including, for example, penalties for deviations from the schedule of take-off / landing operations, failure to keep the CFMU time slots, or for too long taxiing cycles. The article presents restrictions on taxiing of aircraft, integration with other airport operations, decision problems and applied algorithms, groups of restrictions on taxiing of aircraft, scheduled flight table, dependencies between individual operations, positioning of aircraft.

Schlüsselwörter

  • air traffic control
  • aircraft operations
  • airport
Uneingeschränkter Zugang

Comparative Analysis of the Fuel Consumption of Vehicles Equipped with Various Types of Automatic Transmissions

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 119 - 124

Zusammenfassung

Abstract

The growing number of vehicles moving on Polish roads equipped with various types of automatic transmissions prompted the authors of this publication to carry out research to assess the impact of the use of this type of transmission on the fuel consumption of these vehicles. The presented article presents a comparative analysis of the fuel consumption of vehicles of different manufacturers equipped with automatic transmissions moving in specially prepared driving cycles for research purposes. In the developed driving cycle, the vehicle speed was gradually increased every 10 km/h, maintaining each speed for a period of at least 30 seconds in order to stabilize the measurement results. The tests were carried out for various load stages of the drive system. Load differentiation was made by simulating driving in the prepared cycle for simulated different slopes of the road. The tests were carried out on the MAHA MSR500 chassis dynamometer, and the obtained results for the vehicle moving in automatic mode, where the transmission controller selected the gear ratio according to the programmed algorithm, were compared with the vehicle's fuel consumption for the vehicle gear selected by the driver in the driving cycle. The control software used to test the chassis dynamometer allows taking into account the increasing resistance of traffic along with the increase of vehicle speed, which greatly approximates the simulated conditions in the laboratory to the conditions on the road. The main purpose of this publication is to check whether using automatic transmissions or other control algorithm of these gears can achieve a reduction in fuel consumption.

Schlüsselwörter

  • automatic transmission
  • fuel consumption
  • control algorithm
  • CVT
  • automotive powertrain
  • road slope
Uneingeschränkter Zugang

Thermal Analysis and Thermovision Laboratory Tests of Electric Brakes

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 125 - 131

Zusammenfassung

Abstract

The purpose of this article was to show two thing thermal issues theory and thermovision tests in the laboratory. The main idea of this article was to describe the thermal issues theory of interesting problem base on the thermovision tests of new type electric brake prototype. After the creation of new product the designer needed to know how behave the prototype of the brake during tests with higher energy which could increase the temperatures on the object in our case of the electric brake prototype. The first step in that kind of issues was thermal analysis, which is very useful to define and subscribe the thermal issues. The second step it was measurement of the temperature, which was really significant during the electric brake tests. It was really important to check the temperature of engines. If there was some influence to the brake during braking. One of the method was using special thermal camera. The camera was checking the temperature during whole test after beginning the test to the end of the trial. The full spectrum of the temperature allowed the author to verify if there was some influence of temperature to the new electric brake prototype. The thermocouple was other type of sensors, which was normally used in our laboratory methodology to check temperature during the test. The pyrometer was other type of the method, which was used to measure the temperature after the test. The results of this measurement were subscribed in this article.

Schlüsselwörter

  • laboratory testing
  • electric brake
  • temperature tests
  • braking process
  • thermovision
Uneingeschränkter Zugang

The Application of Genetic Algorithm in the Assignment Problems in the Transportation Company

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 133 - 140

Zusammenfassung

Abstract

The article presents the problem of the task assignment of the vehicles for the transportation company, which deals with the transport of the cargo in the full truckload system. The presented problem is a complex decision making issue which has not been analysed in the literature before. There must be passed through two stages in order to solve the task assignment problem of the vehicles for the transportation company. The first stage is to designate the tasks, the other one is to determine the number of the vehicles that perform these tasks. The task in the analysed problem is defined as transporting the cargo from the suppliers to the recipients. The transportation routes of the cargo must be determined. In order to solve the task assignment problem of the vehicles, the genetic algorithm has been developed. The construction stages of this algorithm are presented. The algorithm has been developed to solve the multi-criteria decision problem. What is more, the algorithm is verified by the use of the real input data.

Schlüsselwörter

  • assignment problem
  • genetic algorithm
  • multi-criterion optimization
  • transportation company
Uneingeschränkter Zugang

CFD Simulations as a Support of Experimental Research in a Rapid Compression Expansion Machine Facility

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 141 - 147

Zusammenfassung

Abstract

The main aim of this study to reproduce methane combustion experiment conducted in a rapid compression-expansion machine using AVL FIRETM software in order to shed more light on the in-cylinder processes. The piston movement profile, initial and boundary conditions as well as the geometry of the combustion chamber with a prechamber were the same as in the experiment. Authors by means of numerical simulations attempted to reproduce pressure profile from the experiment. As the first step, dead volume was tuned to match pressures for a non-combustion (air-only) case. Obtained pressure profile in air compression simulations was slightly wider (prolonged occurrence of high pressure) than in the experiment, what at this stage was assumed to have negligible significance. The next step after adjusting dead volume included combustion simulations. In the real test facility, the process of filling the combustion chamber with air-fuel mixture takes 15 s. In order to shorten computational time first combustion simulations were started after the chamber is already filled assuming uniform mixture. These simulations resulted in more than two times higher maximum pressure than recorded in experiments. It was concluded that turbulence decays quickly after filling process, what was also confirmed by next combustion simulations preceded by the filling process. Then the maximum pressure was significantly decreased but still it was higher than in the experiments. Based on the obtained results it was assumed that the discrepancy noticed in air cases is further increased when combustion is included. Moreover, the obtained results indicated that pre-combustion turbulence level is very low and suggested that either piston profile movement is not correct or there is high-pressure leak in the test facility.

Schlüsselwörter

  • AVL FIRE
  • self-ignition
  • RCEM
  • CFD
  • knocking combustion
Uneingeschränkter Zugang

Analysis of Hazards Occurring During the Use of Hydrazine

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 149 - 154

Zusammenfassung

Abstract

The article presents the safety issue bonded to the Polish Air Force F-16 multirole aircraft. The authors pointed out the issue of fuel used for emergency supply system of these aircrafts. The article emphasized the fact that these aircrafts require special fuel with designation H-70, which is 70% aqueous solution of toxic hydrazine. For this reason, the rescue services of Polish Air Force bases where Polish F-16 are stationed had to be adjusted accordingly. Just as importantly, authors noticed that in the event of an emergency landing of this aircraft at different airports could receive difficulties associated with the possible leakage of hydrazine, or its neutralization in the absence of specialized Hydrazine Response Team, which are part of the Airport Rescue Group. After the introduction of new aircraft for use in the Polish Air Force (in this case F-16 multirole aircraft), it is necessary to analyse the safety of their use in the context of potential places on which they can land. This is related, among others, to the safety of managing liquid fuels. In the case of F-16 aircraft, one must bear in mind besides the F-34 fuel, also hydrazine (H-70). The article presents a functional diagram of EPU system of emergency power supply EPS of F-16 multirole aircraft.

Schlüsselwörter

  • aviation fuel
  • hydrazine
  • airport rescue group
Uneingeschränkter Zugang

Influence of Geometric Characteristics of the Bomb-Fluger System on its Dynamics

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 155 - 163

Zusammenfassung

Abstract

The article presents the results of numerical simulations of the bomb-fluger system drop. This system consists of two rigid bodies – a bomb and a fluger, which are connected by a biaxial joint. For the analysis, an author's program was used to simulate the bomb-fluger system drop. Influence of the characteristic points of the system on its stability and dynamics was investigated. Particularly, locations of a bomb mass centre, a fluger mounting point, a fluger aerodynamic focus were tested. The article presents a model of the examined bomb in the wind tunnel, characteristic points of a bomb-fluger system, waveforms of values rate of change angles and the values of angles for different distances, waveforms of values of the angle of nutation and the pitch angle of the fluger relative to the bomb, diagrams of examined points of the location of the centre of the mass and pressure of the fluger, waveforms of values rate of change angles and the values of these angles for different locations of the centre of the mass of the fluger, waveforms of values of the angle of nutation and the pitch angle of the fluger relative to the bomb for different locations.

Schlüsselwörter

  • guided bombs
  • bomb-fluger system
  • aerodynamics simulations
Uneingeschränkter Zugang

The Evaluation of the Efficiency of Active Control System for Aerial Bomb

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 165 - 174

Zusammenfassung

Abstract

The article presents the results of numerical simulation of a laser-guided bomb, which is dropped in calm weather conditions. The prototype of such a bomb was developed at the Air Force Institute of Technology. It was a result of the modification process of the classical training bomb. The modification consisted of building on the bomb's board a detection system to track targets that are designated by laser and a control system to adjust bomb’s glide path to precisely strike the target. In the simulation research, geometric and mass characteristics of the classical training bomb were used. Aerodynamic characteristics of the bomb have been determined using commercial software PRODAS. Using the mathematical model of the bomb spatial motion and model of the laser detection system series of simulations were performed. The main goal was to determine the effectiveness of the adopted construction solution. Therefore, simulations were performed for various initial positions of the bomb and fixed position of the target. It allowed finding the set of control laws coefficients giving the most accuracy of the bomb. The influence of structural modifications of the detection system on the possibility of effective detection and location of the target was also investigated. In the article, exemplary results of numerical calculations performed with the author's software are also shown.

Schlüsselwörter

  • simulation
  • PID controller
  • laser-guided bombs
Uneingeschränkter Zugang

Numerical Modelling of Combustion Process with the Use of ANSYS FLUENT Code

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 175 - 186

Zusammenfassung

Abstract

The article presents the modelling of the combustion process of liquid fuels using professional ANSYS FLUENT software. This program allows modelling the dynamics of compressible and incompressible, laminar and turbulent flows as well as heat exchange phenomena with occurrence and without chemical reactions. The model presented in the article takes into account the influence of the gas phase on the liquid phase during the fuel combustion process. The influence of velocity and pressure of the flowing gas and the type of flow has a significant impact on the combustion of liquid fuels. The developed model is fully reliable and the presented results are consistent with experimental research. The occurrence of a laminar sublayer in a turbulent flow was confirmed, and the thickness of this layer and the turbulent layer significantly influences the course of the combustion process. The use of the flat flow model reflects the basic phenomena occurring during the combustion of liquid fuels under turbulent conditions. The use of the program for flows with different flow velocity profiles is justified. It gives important information about the processes taking place during the combustion of liquid fuels. The results of numerical tests are presented graphically. The article presents graphs of velocity field, absolute pressure, power lines, temperature and density.

Schlüsselwörter

  • liquid fuels
  • combustion processes
  • turbulent flow
  • combustion process model
  • ANSYS FLUENT
Uneingeschränkter Zugang

Researches of a Combustion Engine Fuelled with a Fuel-Water Microemulsion

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 187 - 196

Zusammenfassung

Abstract

The emulsion is a mixture of two or more insoluble liquids. Microemulsion is the emulsion with particles dimension in a range of one micrometre and smaller. Such a microemulsion of water and diesel fuel will create a novel quality and allows one to simultaneously achieve environmental and economic effects, as well as eliminate the ad-verse impact of normal emulsions, or adverse effects of water injection into the engine intake system or directly into the combustion chamber, as well as the sequential injection of water directly into the combustion chamber. Application of microemulsion of water and diesel to fuel diesel engine positively affects the combustion process through the catalytic impact of microparticles of water, and improves the process of preparation of the microemulsion injection into the combustion chamber as a result of water microparticles’ microexplosions. This article presents the investigation results of an internal combustion engine fuelled by an emulsion of water and diesel fuel and fuelled by emulsion of FAME and water. It therefore seems appropriate to a strong increase in the degree of dispersion of water droplets in the emulsion by applying the methods to obtain the size of water droplets on nanometric range. This should dramatically improve both the stability of emulsion and its influence on the chemical effects of combustion in diesel engine.

Schlüsselwörter

  • combustion engine
  • combustion processes
  • ecology
  • fuel-water microemulsions
Uneingeschränkter Zugang

The Use of Laser Equipment to Optimize the Operating Parameters of the Fuel Injector of Combustion Engine

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 197 - 206

Zusammenfassung

Abstract

The conducted tests were aimed at determination of the drop diameters and shaping of the velocity field at different configurations of the test injector. The test results allowed defining the relationship between the injector configuration and the distribution of velocities and dimensions of drops in the fuel stream. The effect of the fuel viscosity and injection pressure on the dimensions of fuel drop diameters and the distribution of the velocity field of drops in the stream were tested. The tests were carried out on a special test rig with a fixed volume chamber. The measurements were carried out with the use of laser Doppler measurement systems (PDPA, LDV). The tests were conducted for seven different fuel types varying in viscosity and surface tension. In addition, the injection pressure from 50 MPa to 130 MPa was applied. The test results allowed determining the relationship between the injector structure configuration, fuel types and fuel additives, and the distribution of velocity and an atomisation spectrum of drops in the fuel stream, and the air impact on the fuel stream.

Schlüsselwörter

  • combustion engine
  • fuel injection
  • laser methods
  • size drop distribution
Uneingeschränkter Zugang

Technical and Economic Analysis of Various Solutions of Fuel Supply Systems in Marine Diesel Engine of Ships Sailing in the Control Emission Areas (ECA)

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 207 - 216

Zusammenfassung

Abstract

In the article, legal norms regarding the reduction of sulphur content limits in exhaust gases in special areas were presented. Then an overview of various solutions for supplying the marine engine with heavy fuel, distillation fuel and gas was made. In addition, the problem of using low-sulphur fuels in internal combustion engines was described. The presented solutions are a response to the latest provisions being part of the VI Annex of the MARPOL Convention, which entered into force on 01.01.2015. These provisions constitute that sulphation of fuel used in Emission Control Areas (ECAs) may not exceed 0.1%. Then, to meet the requirements, the conditions of using heavy fuels for supplying diesel engines were presented. Individual solutions such as the use of low-sulphur fuels, exhaust gas scrubber assembly, and the supply of liquefied natural gas (LNG) from the technical side were shown. Besides, the advantages and disadvantages of each of them were also indicated. In the following part, the economic analysis of the selected ship was made. Its purpose was to evaluate economically in the assumed time of operation, and then select the optimal solution for a given unit. For the comparative analysis, the use of low-sulphur fuels was used; the assembly of the scrubber, as well as the adaptation of the unit to use liquefied natural gas (LPG). The article was finished with conclusions; the most important of them is that the use of fuels with reduced sulphur content is the most expensive solution for the selected ship. The cost of the remaining solutions is at a comparable level, but they require greater interference in the ship’s construction.

Schlüsselwörter

  • environmental protection
  • sulphur compounds
  • power engines
  • marine scrubbers
  • shipping
Uneingeschränkter Zugang

Analysis of Abrasive Wear of Selected Aircraft Materials in Various Abrasion Conditions

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 217 - 222

Zusammenfassung

Abstract

The use of composite materials is continuously increasing in modern transport. This process is especially noticeable in aviation. The mass percentage of epoxy resin composites in contemporary aircraft constructions is usually higher than 50%, and these materials must meet increasingly demanding requirements. In these circumstances, in addition to mass and strength, it is necessary to predict other properties of the material, such as abrasion resistance. The article presents the analysis of the process of abrasion of carbon fibre reinforced polymers reinforced with various fillers. Straight carbon fibre mats were used for the tests. In addition, powders of pumice, alumina, silicon carbide, and glass microspheres at various concentrations in relation to the matrix were used as fillers. In order to investigate the influence of external factors on the abrasion process, each group of samples was subjected to abrasion under different external conditions: in an insulated environment, in the presence of water and loose abrasives: brown fused alumina (BFA) and white fused alumina (WFA). The measurements were carried out using a precision balance and an electron microscope. The results allow concluding on which kind of filler and in what concentration contributes to improvement of the abrasion resistance of the composite material the most. In addition, it was found that the conditions in which abrasion occurs have a very large impact on the course of this process.

Schlüsselwörter

  • composite materials
  • tribology
  • carbon fibre reinforced polymer (CFRP)
  • aerospace materials
Uneingeschränkter Zugang

The Influence of Granulation and Content of Polyester-Glass Waste on Properties of Composites

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 223 - 229

Zusammenfassung

Abstract

Glass fibre reinforced composites are used in many branches of industry. Polyester-glass laminates serve as structural material in shipbuilding (e.g. hulls of units, superstructures), in railways, automotive (e.g. elements of car bodies and interior fittings, roofs of wagons, cisterns) or aviation (e.g. aircraft fuselages, fuel tanks, completion beaks and ballasts). Factors affecting the increase of their use include low specific gravity, optimal strength properties, corrosion resistance. This is associated with a large amount of post-production and post-use waste. The recycling problem of these materials remains unresolved. The article presents the technology of processing polyester-glass waste in order to obtain a recycle with a specific granulation. The selected technology for the production of layered composites with reinforcement in the form of recycle is described. For testing, granulation was selected for 1.2 and 3 mm, as well as content: 0%, 10%, 20% and 30%. Using the water-cutting method, samples were prepared according to the standard static tensile test for plastics. The tests were carried out using a universal testing machine as well as an extensometer for samples with granulation of 1.2 mm and 3 mm, as well as the selected recycled percentage. Obtained results of the research indicated that granulation as well as content affects the strength properties of composites. As the granulation increases, at the same content, the material gains less deformation. The increase in the amount of the recycle reduces the strength properties of the material, and also due to the decrease in the deformation value - the material becomes brittle.

Schlüsselwörter

  • recycling of composites
  • polyester-glass waste
  • tensile test
  • strength properties
Uneingeschränkter Zugang

The Possibility of Modifying the Lubricity of Transmission Oils in Industrial Gears

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 231 - 237

Zusammenfassung

Abstract

The study deals with the issue of durability extension of multi-phase gears working under temporary or constant loading. The tests were performed for transmission oils used in power transmission systems of beet washers of DC type used in sugar plants. The lubricity parameters of oils and the possibilities of their modification through introduction of low-friction additives to the oil were studied. Additionally, the noise level emitted by working gears was measured before and after addition of the modifier. Lubricity tests were performed on semi-Timken apparatus, on which friction pairs friction roller- roller were tested with the use of oils extracted from the gear. SoundMeter application with MIC002 microphone adaptor was used for measurement of the noise level emission. Tests results have confirmed efficiency of the modifiers as higher values of friction loading were obtained and the noise emission level was reduced. It has been proven that in real operation systems, there is a possibility to increase the value of transmission oil lubricity parameters, which has a direct impact on durability of friction pairs of a gear during its operation.

Schlüsselwörter

  • lubricating oils
  • gear box
  • friction
  • lubrication
  • boundary layer
  • low friction additives
  • acoustic emission
Uneingeschränkter Zugang

Application of Similarity Method of Distance Courses Describing the Elements Content in Typical Cement Concrete

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 239 - 246

Zusammenfassung

Abstract

The article concerns the use of similarity analysis of distance course in the internal area of cement concrete intended for airfield pavements. Research procedure was presented and the obtained laboratory tests results were discussed. The contents of diversified elements in four zones (cement matrix, contact area between air pores and cement matrix, contact area between fine aggregate and cement matrix and contact area between coarse aggregate and cement matrix) were specified by using scanning electron microscope. Based on the results obtained diagrams similarity of the analysed of areas in the concretes were prepared. The purpose of this article has been the assessment of an opportunity to apply the analysis of similarity of distance courses with respect to cement concrete intended for airfield pavements. The scope of article consisted of two stages. The analysis included cement concretes intended for airfield pavements, in compliance with requirements. The thermal analysis method was used; the selected concrete components were determined by means of quantitative method. The occurrence of crystalline stages was determined using X-ray diffraction method. Internal structure of concrete composite was assessed with the scanning electron microscope.

Schlüsselwörter

  • transport
  • airfield pavements
  • cement concrete
  • concrete microstructure
  • analysis of similarity
Uneingeschränkter Zugang

Python Programming Language as a Tool for Creating Three-Dimensional Figures of Glider Aerobatics

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 247 - 253

Zusammenfassung

Abstract

The article presents the possibilities and validity of the implementation in the field of developing mathematical models for aerobatics trajectory. Proposing a catalogue of three-dimensional figures and those described mathematically will allow improving judging and scoring level, as well as the art of piloting in aerobatics. In the first chapter, article describes the processes of aerobatic flight, judge evaluation method and the current state of technology supporting the scoring process. The second chapter presents the capabilities of the Python programming language, which will be a tool for the construction of three-dimensional models. The third chapter of this article is a description of the comparative analysis of ideal trajectories and obtained in real flight. This chapter also demonstrates the validity and necessity of introducing new standards for assessing aerobatic flights. Aerobatics flights and judging, intelligent system to control aerobatic flights, three-dimensional models of aerobatic flights are presented in the article. The article concerns on use modern technologies to support the judges during the competition. The introduction of ASSD + PL system and the possibility of implementing designed models of aerobatic figures open new paths for improving the art of pilotage and arbitration.

Schlüsselwörter

  • aerobatics
  • general aviation
  • fly trajectory
  • mathematical programming
Uneingeschränkter Zugang

The Initial Analysis of the Aerodynamic Characteristics of a 3D Printed Model of an Aircraft

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 255 - 262

Zusammenfassung

Abstract

The aerodynamic research into models of an aircraft aims at creating the main characteristics of aerodynamic forces and moments and the aerodynamic characteristics of coefficients of aerodynamic forces and moments, based on real dimensions. The method of 3D printing was used to create a model of an aircraft. The model with the previously set printing parameters and commands for a 3D printer, in the right order, was imported into MakerBot Print. The final stage was printing the model. The printed components of the model of an aircraft were imperfect due to the incorrectly set printing parameters. The model with the previously set printing parameters and commands for a 3D printer, in the right order, was imported into MakerBot Print. The final stage was printing the model. The printed components of the model of an aircraft were imperfect due to the incorrectly set printing parameters. The printing parameters were corrected in the next printing sessions so the surfaces of the components were good enough and grinding was unnecessary. Some excess material was removed in each of the printed components, and the slots were cleaned. Then, the individual models were put together.

The article describes the technique of creating a model of an aircraft to map its exact geometry for experimental wind tunnel research. 3D printing enables us to experimentally investigate a created geometry, in particular to investigate further prior to releasing an aircraft to service. The 3D model employs the model created in line with the previous CFD analysis.

Schlüsselwörter

  • air transport
  • simulation
  • wind tunnel
  • experimental analysis
  • gyroplane
Uneingeschränkter Zugang

Computational Modelling of the Fuel Injection and Combustion in a Diesel K6 Rotary Engine

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 263 - 276

Zusammenfassung

Abstract

This paper outlines the methods and results of computations completed using the ANSYS Fluent code modelling the fuel injection and combustion within the K6 engine, a new form of rotary engine in which the fuel is injected in an arc across the top of the cylinder. The model uses the DPM Model in conjunction with a dynamic mesh and non-premixed combustion models to treat the injection as liquid diesel evaporating to C12H23. The outcomes of this model are presented in images displaying the distribution of temperature, and fuel and CO2 concentrations. The limitations pertaining to the maximum injection angles are also studied. The simulation is found to be effective and the results suggestive of successful, clean and complete combustion while presenting some matters, which require further investigation. The article presents temperature within the combustion chamber at various crank angle degrees, ) velocity of fluid within the combustion chamber, effects of impingement with injector offset on temperature and fuel concentration, fuel concentration demonstrating impingement, in cylinder temperature curve

Schlüsselwörter

  • combustion engine
  • combustion process
  • combustion factors
  • fuel injection
  • ANSYS Fluent code
Uneingeschränkter Zugang

Modelling of Physical Phenomena in the Vertical Velocity Measuring Circuit for Process of Designing the SWPL-1 Helmet-Mounted Display System

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 277 - 284

Zusammenfassung

Abstract

The article presents the selected methods of identifying static and dynamic properties of the measuring paths to the extent necessary for the proper integration of on-board systems with the helmet-mounted flight parameter display system. It presents the methods of identifying static and dynamic properties of the WR-10MK on board variometer as one of more difficult identification elements. Its identification was carried out on the basis of the basic dependencies of the International Standard Atmosphere and the instruments construction’s parameters. It built a mathematical model describing the physical phenomena associated with vertical speed measurement. This model differs from the models found in the literature in terms of detail and description accuracy. On this basis, in the Simulink environment, it built a simulation model corresponding to its mathematical model. The non-linear model was the starting point for the construction of the linearized model based on the operator transmittance. The developed models were evaluated for errors of vertical speed’s dynamic indications. This allowed assessing the usefulness of the individual models for further works on ensuring the correlation of indications of the on-board variometer and the SWPL-1 helmet-mounted flight parameter display system. The presented simulation models include design details, as well as the characteristics of technological errors and disturbances of a stochastic nature. Another approach to the issue of identification is to use the characteristics provided by the manufacturer in the form of approximate characteristics of a module.

Schlüsselwörter

  • transport
  • avionics
  • helmet-mounted display systems
  • errors of the vertical velocity measurement
Uneingeschränkter Zugang

Application of Multi-Criteria Optimization to Choose Variants of Hardware Architecture for the SWPL-1 Helmet-Mounted Display System

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 285 - 292

Zusammenfassung

Abstract

The paper presents the structure and basic properties of the SWPL-1 helmet-mounted flight parameter display system, constructed for the Mi-17 helicopter with analogue systems and on-board instruments. It describes the basic components of the SWPL-1 system and on board components cooperating with the SWPL-1 system necessary to ensure the imaging system’s operation (including the ADU-3200 central unit for aerodynamic data and the GPS-155XL satellite signals receiver). It presents the architecture, the principle of operation, and the main constituents of the SWPL-1 helmet-mounted flight parameter system, as well as the standards of data transmission used in digital communication between the SWPL-1 system and on-board systems (installed on the Mi-17 helicopter). It describes the scope and manner of pilot and navigation data presentation as well as control of drive unit operation parameters in detail. It presents selected optimization methods for tasks executed in the helmet mounted system’s life cycle. The particular stages of the life cycle were described in detail, from the earliest stages of needs identification, through the analytic and conceptual phase, then the implementation stage, and ending with the operation stage. It introduces tasks for optimization and related methods into the process of creating the new system at every stage of its implementation. It presents one of the methods of multi-criteria optimization based on the experts’ assessment of choice of a variant of the helmet-mounted flight parameter display system’s hardware architecture in detail.

Schlüsselwörter

  • transport
  • avionics
  • helmet-mounted display systems
  • hardware architecture
  • multi-criteria optimization
Uneingeschränkter Zugang

Using Thermovision for Temperature Measurements During Turning Process

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 293 - 298

Zusammenfassung

Abstract

In metal cutting industries, machining processing, especially turning operation is very basic type of machining. For certain processes in manufacturing, it is favourable and necessary to have certain knowledge about heat generation and temperature rise (including average and maximum temperature) during machining process. Increment in maximum temperature at clearance face or at rake face of cutting tool causes the reduction in life of tool. Similarly, the quality of machined surface, a metallurgical structural alteration in tool and workpiece material also depends on the maximum temperature, temperature gradient and cooling rate of both tool and workpiece. Certain physical and chemical reactions that are developed during the cutting process are directly connected with tool wear, power consumption, surface roughness on work piece material and cutting temperature. The natural low of thermal energy gives significant relationship between cutting temperature and cutting parameters in order to improvement of cutting tool’s wok efficiency, quality and accuracy. The heat distribution in cutting tool, in formed chip and in workpiece material strongly depends on (mechanical and chemical) properties of cutting tool and workpiece material, cutting speed, depth of cut, feed rate, nose radius, geometry of tool, type of coolant used and other parameters. This work presents some results of research done during turning steel 235JR realized on conventional lathe CDS 6250 BX-1000 with severe parameters. These demonstrate the necessity of further, more detailed research on turning process temperature, realized for different materials.

Schlüsselwörter

  • lapping
  • infrared measurement
  • lapping plate temperature
  • lapped surface quality
Uneingeschränkter Zugang

Analysis of Changes in Traffic Rules and Assessment of Their Impact on Road Traffic Safety

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 299 - 308

Zusammenfassung

Abstract

Road safety is an important social issue. Hence, changes in road traffic rules have a large influence on travel safety improvement. One of the major issues to be addressed is the speed limit of motor vehicles and radar speed measurements. Moreover, road traffic rules impose the obligation to wear safety belts during driving, carrying children in car safety seats and they put a ban on drink driving as well as driving under the influence of other intoxicating substances that have a negative influence on the driver’s physical condition and driving skills. This study analyses changes in traffic rules and provides assessment of the way they affect road traffic safety in Poland. The study presents an analysis of the issues connected with road vehicle operation and safety of the passengers including: wearing safety seat belts, use of children car safety seats, vehicle lighting, speed limit. Such issues as the proposed changes in breathalyzer use and implementation of safety systems to provide road users with safety have been addressed.

Schlüsselwörter

  • transport
  • road transport
  • traffic rules
  • safety
  • vehicle operation
Uneingeschränkter Zugang

Possibilities of Extension of Gear Oil Service Life in Rail Vehicles

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 309 - 316

Zusammenfassung

Abstract

The study deals with the results of operational tests of gear oils used in a regional railway transport system. The character of the aging process and the impact of gear oil operation on the main factors determining further usability of gear oil have been defined on the basis of the results of carried out tests. It was proved that transport systems lack reliable convenient diagnostic methods for gear oil used during the process of operation. One of the criteria taken into consideration in decision-making is the period of oil change imposed by the gear manufacturer. The long process of oil application is accompanied by physicochemical changes, which cause degradation of its properties. This phenomenon is referred to as oil aging. This fact can cause loss of viscosity, increase in the amount of pollution, and in effect a decrease in the ability to provide a durable boundary film. The lubricating ability of oil decreases as well. An increase in the amount of pollution is caused by interaction of the collaborating friction elements and by pollutants coming from the gear environment. These changes are of permanent character and reflect the state of new characteristics referred to as operational characteristics. Gear oils have a certain lubricating ability, which is a critical parameter. This study is an attempt to find a way of the oil service life extension and convince the propulsion systems manufacturers that reduction of costs connected with rail vehicle maintenance does make sense.

Schlüsselwörter

  • transport
  • rail vehicle
  • lubricity
  • ignition temperature
  • concentration of wear products
  • kinematic viscosity
Uneingeschränkter Zugang

Analysis of LDV Operation Manner in Terms of its Environmental and Economical Indexes

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 317 - 323

Zusammenfassung

Abstract

Environmental protection is becoming an increasingly important issue in every area of life. In recent times, a great emphasis has been placed on reducing the negative impact of automotive on human health at every stage of the vehicle's life. The most common impact of cars on the environment is the emission of pollutants from the exhaust system, created during the combustion of fuels in internal combustion engines. For this purpose, legislators introduce emission standards that must be met at the stage of vehicle approval for a given market. To meet these requirements, vehicle manufacturers modify the design of the drive units, body, and chassis to reduce weight and improve aerodynamic properties. This approach is methodologically correct because it is possible to compare the results obtained for different vehicles, but in real operation the level of harmful exhaust compounds, emissions and fuel consumption depend very much on the way the vehicle is used. As a manner of operation one can understand a variable load in the form of passengers or cargo, driving style, share of urban, extra-urban and motorway driving, terrain formation, ambient temperature and others. This article addresses issues related to the assessment of the impact of the light commercial vehicle operation manner on fuel consumption and the emission of harmful exhaust compounds. The problem was analysed in terms of the difference in vehicle load and driving style. Exhaust emission measurements were carried out using PEMS (Portable Emission Measurement System) analysers, which are state of the art devices for measuring exhaust emission in real operating conditions, called RDE (Real Driving Emissions).

Schlüsselwörter

  • exhaust emission
  • road transport
  • RDE
  • PEMS
  • ecodriving
Uneingeschränkter Zugang

Modelling of a Permanent Magnet Motor with an Inverter in a Drive System of a Car – Part II

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 325 - 335

Zusammenfassung

Abstract

The article presents a mathematical model of a permanent magnet motor, powered by a three-phase source of sinusoidal voltage, and a control method. Cooperation between numerical integration algorithms in the differential equation system of the motor and an inverter has been verified. The results of numerical simulations are presented in a graphic form. This article is an extension of the publication [12], in which a model of a drive system was proposed, consisting of: a battery, a supercapacitor and a method of controlling these energy sources during a driving cycle of a vehicle. For vector control, the mathematical model of a synchronous machine in the dq coordinate system is the most common one. The most important feature of this control method is the fact that the iq component of the rotor current vector determines the value of motor torque, and the component id – the value of magnetic flux. In the article, the emphasis is put on how inverters work. Their basic task is to generate such currents iabc or voltages uabc to obtain torque without ripples. It leads to development of different control concepts for achieving this goal, which are related to the modelling of magnetic fluxes in a stator and in an inverter.

Schlüsselwörter

  • electrical machines
  • permanent magnet motor
  • inverter
  • electric drive control system
Uneingeschränkter Zugang

Impact of the Geometry Accuracy of the Cycloidal Gear Output Shaft with Pins of the Efficiency and Vibrations

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 337 - 345

Zusammenfassung

Abstract

Cycloidal gear is characterized by [2]:

– Large ratio (up to 171:1) from one stage of reduction, which minimizes the weight and dimensions of the reducer.

– Minimizing the centrifugal forces as the only high-speed element is the input shaft with an eccentric bearing.

– Minimizing internal clearance due to simultaneous meshing of a large number of teeth. In contrast to gears with involute teeth, 10-50% of teeth are found in cycloidal gears with simultaneous meshing. It depends on the size of the gear and the load. The minimum number of teeth engages when running in bulk.

– Low noise and low vibration for large torques and variable speeds.

– High efficiency in a wide range of loads, because rolling elements are used in every place responsible for the transfer of torque.

– Permissible load up to 500% of the rated torque.

All above mention point lead into long-term and trouble-free operation, however the above features require high accuracy. The article described comparison of efficiency, vibration and noise obtained for 3 cycloidal gear modules:

1. Two-disc gear with single rollers for both discs (Chmurawa prototype [1]).

2. Three-disc gearbox with separate rollers for each disc (new idea) with gear components: output shaft with pins, housing with rollers (wheel with internal tooting), and input shaft, made with the manual lathe.

3. The same three-disc gearbox with output shaft with pins made with the CNC. Different levels of accuracy and thus corresponding vibration patterns were obtained.

Schlüsselwörter

  • cycloidal gear
  • efficiency
  • vibrations
Uneingeschränkter Zugang

Electrical Properties Study of Fibre Reinforced Polymeric Materials Used in Aircraft Structures

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 347 - 353

Zusammenfassung

Abstract

Aircraft are exposed to lightning strikes. Lightning strike protection (LSP) devices involve additional weight of the aircraft. Therefore, multifunctional materials that allows the conductivity of electrical current and, simultaneously, holds the mechanical properties required to withstand the typical conditions for an aerospace material are widely researched. A typical resin used in aviation is an insulator, so main research is done to reduce its resistance. On the other hand, the type of reinforcement can have a large influence on the electrical conductivity in the plane of reinforcement. The aim of the article is to evaluate the effect of the type and the basis weight of reinforcement on the electrical conductivity. For this purpose, with the use of a hydraulic press, different four-layer composites based on epoxy resin were produced. Each differing is in combination of carbon, glass layers and their basis weight (from 48 kg/m2 to 245 kg/m2). The measuring proceedings were carried by an RMS multi meter and, more accurate, by an LCR meter with 4 selectable test frequencies. The measurements were made both along the strand fibres and at a 45-degree angle. The results made it possible to determine which reinforcement of aircraft composites should be selected at the aircraft design level to provide increased electrical conductivity along the reinforcement fibres and thus influence one of the factors affecting the protection of the aircraft against the effects of lightning.

Schlüsselwörter

  • composite materials
  • electrical conductivity
  • carbon fibre reinforced polymer (CFRP)
  • glass fibre reinforced polymer (GFRP)
  • aerospace materials
  • lightning strike protection (LSP)
Uneingeschränkter Zugang

High Voltage Batteries Diagnostic

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 355 - 360

Zusammenfassung

Abstract

Hybrid vehicles history begins between XIX and XX century because then has been constructed first hybrid vehicle project. The first men who produced electric propulsion mounted in front hubs connected with generator powered by spark ignition engine was Ferdynand Porsche. Vehicle was called Lohner – Porsche Electromobile. The first en masse produced hybrid vehicle was the first generation Toyota Prius. These model premiere was in 1996, and production started one year later. Vehicle was equipped in 1,5 dcm 58 hp spark ignition engine with added electric propulsion generated 40 mechanical hp. There has been mounting 72 hp spark ignition engine and 44 hp electric generator since 2000. Fuel consumption of these model was 5 liter on 100 km. Beginning XXI century 95% hybrid vehicles were Toyota Prius. The biggest competitor of Toyota Prius was Honda Insight. Lexus and Mercedes started producing hybrid vehicles few years later. The most popular brands selling hybrid vehicles are Toyota and Lexus – Toyota Motor Corporation.

Article describes high voltage battery example diagnostic possibilities in a hybrid or electric vehicle. Constructing vehicle models using two propulsion systems (spark ignition engine and electric generator) cause development and increase control system devices. The measurements has been made by using various diagnostic devices for example: diagnostic scanner mega macs 66, high voltage battery tester. Reading faults code is not enough so it is necessary to use data list what describes this article.

Schlüsselwörter

  • hybrid vehicles diagnostics
  • high voltage battery
  • HV battery test
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Characteristic Features of the Process of Growth in the Mileage of Hybrid Vehicles

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 361 - 368

Zusammenfassung

Abstract

For a few years, the sales of motor vehicles with hybrid drive systems (referred to as “hybrid vehicles” or “HVs”) have been rapidly growing. However, there is a lack of information about the intensity of operation of vehicles classified in this category, which is completely new. A calculation procedure has been presented that enabled evaluation of the HV mileage growth rate. An analysis of this rate provides grounds for forecasting the changes that are likely to take place in the fleet of motor vehicles, such as the progress in the process of replacement of conventional vehicles with vehicles with alternative drive systems, and this may be a basis for predicting the reduction in fuel consumption and exhaust emissions. Models of the HV mileage growth process have been defined for three different countries. They indicate high mileage growth rates in the initial period of vehicle operation, e.g. until the fourth year of operation of the Auris H cars. The highest mileage growth rates in this period were observed in the Netherlands and Poland. In Germany, this rate was lower by 41%. Significant differences in the intensity of vehicle operation have been observed between the behaviour of HV owners in the countries under analysis. A considerable drop in the annual HV mileage as early as in the fifth and sixth year of vehicle operation is an alarming signal.

Schlüsselwörter

  • hybrid vehicles
  • mileage of hybrid vehicles
  • estimation of mileage growth models
Uneingeschränkter Zugang

Reduction of Pressure Rise Rates in Boosted HCCI Engine Using Advanced Valve Actuation Strategies

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 369 - 376

Zusammenfassung

Abstract

Homogeneous Charge Compression Ignition (HCCI) is a promising low temperature combustion technology which offers high fuel efficiency and extremely low exhaust emissions. However, there are still some pending issues to be resolved before the technology will achieve mass production level. Namely, combustion controllability should be improved and HCCI operating range should be widen. The latter is constrained by excessive combustion rates under high loads. In this study, advanced variable valve actuation strategies were applied to control auto-ignition timings and combustion rates. The examinations were conducted using single-cylinder research engine fuelled with directly injected gasoline. The HCCI combustion was achieved using negative valve overlap technique. The engine was run under boosted conditions, in an operation regime where acceptable pressure rise rate (PRR) level is usually exceeded. Selected valve timing sweeps were carried out within a scope of the experiments to evaluate PRR reduction potential. The obtained results manifested superior combustion controllability. Late exhaust valve closing enabled reduction of the amount of internally re-circulated exhaust, which propagated to the main event combustion. From the intake side, two effects were observed, i.e. variability of the intake air aspiration and variability of the apparent compression ratio. Both phenomena were found to affect combustion timings and rates.

Schlüsselwörter

  • low temperature combustion
  • HCCI
  • valve actuation
  • combustion harshness
Uneingeschränkter Zugang

Friction Losses in a Linear Hydraulic Motor as a Result of the Influence of the Control Structure and Oil Viscosity

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 377 - 384

Zusammenfassung

Abstract

The problem of energy tests of hydraulic systems with hydraulic cylinders, seemingly simple displacement machines, is more complex than that of rotary hydraulic systems. The results of the researches provide an insight into the impact of external loads, required speed, structure of the power supply system, viscosity of hydraulic oil on friction loss, and the efficiency of cylinder drive. The hydraulic cylinder is the strongest structure in the system. Failure of the system is most likely due to failure of the pump supplying the cylinder. The high load of the pump is often caused by the very low energy efficiency of the cylinder, which, despite a relatively low external load, requires high inlet pressure due to large mechanical losses of friction between the piston and the cylinder and between the piston rod and gland. These losses depend on the type of seal used, its shape, the material it is made from, pre-clamp, and the operating parameters of the cylinder. Improperly sealed or assembled seals can cause energy losses of up to 25%. Due to the use of moving seals in the hydraulic cylinder, its energy behaviour is completely different compared to the energy behaviour of a rotary motor, which does not have any seals. The friction force connected with the work of the sealing joints and the mechanical efficiency of the cylinder are determined not only by the external load but also by the method of the applicable supply of the cylinder resulting from the throttling structure, and in particular the pressure level generated in the discharge chamber of the cylinder.

Schlüsselwörter

  • friction force
  • mechanical losses
  • energy efficiency
  • oil viscosity
  • hydrostatic drive
  • hydraulic cylinder
Uneingeschränkter Zugang

Laboratory Tests of Stand-Alone Hydraulic Piezo-Valve

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 385 - 391

Zusammenfassung

Abstract

Flow control inside the aviation landing gear shock absorbers is nowadays performed by fixed orifices or by the half-active spring based valves located inside of the device. All of the mentioned solutions are optimized on limited, mostly to one, landing scenarios due to their non-adjustable nature (even spring based valves are treated as passive due to their lack of actual real-time controllability). The easiest way of full hydraulic fluid flow control is to mount in its way a valve, which is able to seamlessly open and close causing the flow to change in wide range. Unfortunately, most of the used solutions are too large or not fast enough to fit the shock absorber requirements. The most promising way is to design tailor-made valve based on a piezo crystal actuator, which is most suitable due to its size and speed. Such a design has been made and tested by the engineers of the Institute of Aviation in Warsaw in Landing Gear Laboratory. In this article, the author describes test campaign of the hydraulic piezo-valve. Several tests have been made in order to assess the design correctness and to determine the basic parameters of the valve. Achieved results, presented in this article, show the full functionality of the solution in laboratory tests according to the design assumptions [8].

Schlüsselwörter

  • laboratory testing
  • hydraulic valve
  • flow control
  • piezo crystal
Uneingeschränkter Zugang

Evaluation of Interior Air Quality in Terms of Volatile Organic Compounds Emission Inside a New Passenger Car Cabin Depending on the Temperature

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 393 - 398

Zusammenfassung

Abstract

The new passenger car, BMW 225 XE was tested. The results of measurements of concentration of VOCs carried out inside the car cabin depending on the temperature were presented. The investigation was carried out in a special climatic chamber isolated from external factors such as outside air pollutants and weather conditions. The following temperature values have been set: 17ºC, 20ºC, 35ºC and 50ºC. The samples were located inside and outside of the vehicle’s cabin. As expected, the concentrations of each compound increased with increasing temperature (volatility of VOCs increases with the temperature). Values of concentrations obtained in the measurements have been compared with the values of highest acceptable concentration specified in polish law. The article describes the investigation, which was provided in a special climatic chamber. The chamber was isolated from external weather conditions and pollutants. Before each sampling interior of car cabin was ventilated to remove all pollutants from inside. Concentrations of BTX measured in different temperatures were converted to temperature of 20ºC.

Schlüsselwörter

  • vehicles
  • road transport
  • materials
  • VOCs
  • air pollution
  • car cabin
Uneingeschränkter Zugang

Strain Gauge Measuring Plate for Dynamic Tests

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 399 - 404

Zusammenfassung

Abstract

In dynamic tests, especially landing gears, it is necessary to measure and record load levels. In this article, authors present measurement methods used in the landing gear tests on the 10-Ton Drop Test Machine, which is capable of simulating conditions similar to real landing in landing energy dissipation tests. Possible test objects include dampers, shock absorbers, and crash structures and devices. In described case load measurement can be done by several methods where one of them is strain-gauge plate based load measurement. This type of measurement is weighting system under the test object where all forces acting on it are measured. Strain gauge plate is usually tailor-made measurement system, which is composed out of mechanical device (plate itself) equipped with strain gauge force sensors, strain gauge amplification system and recording system. In addition, differences between static and dynamic measurements are described as well as influence of dynamic test conditions on strain gauges behaviour. In the article, authors describe general layout of the system, advantages and disadvantages of the test stand and problems that may appear during measuring. Authors also emphasize how the accuracy of the design affects to the quality of measurement. At the end of the article, advantages and disadvantages of the test stand and problems that may appear during measuring are described.

Schlüsselwörter

  • dynamic tests
  • strain gauges
  • measuring plate
  • test stand
Uneingeschränkter Zugang

The Freight Transport Effectiveness Assessment in the Aspect of the Use of Environmentally Friendly Vehicles

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 405 - 414

Zusammenfassung

Abstract

The freight transport combines the issue of supply services organization for various types of entities, including large shopping centres, stores of various industries, restaurants, work and leisure places, small-scale outlets, or municipal waste shipments. Due to the location of customers, transport services encounter many difficulties related to infrastructural constraints and increased traffic. This adversely affects the safety and obstructions in traffic and air pollution and thus is a disturbing factor for the lives of inhabitants. There is also a growing problem of the smog in large cities (in Poland, for example, Warsaw or Cracow). Traffic safety, minimization of congestion, and minimization of environmental pollution by transport activities are of particular importance in the development of freight traffic organization plans. In connection with the above, in recent years, the use of Environmentally Friendly Vehicles (EFV) in various spheres of human activity has been dynamically developing, and this concerns the cargo transport. Currently, vehicle manufacturers are providing an increasing number of delivery vehicles and trucks. On the other hand, entrepreneurs planning to implement pro-environmental solutions face a decision problem related to the efficiency of a transport system based on the use of EFV as well as the economic validity of implementing this type of innovation. In connection with the above, in this article, the problem of the impact of transport on the environment and the use of EFV in the freight transport was analysed. The main issues related to the functioning of the transport system and its negative impact on the environment has been presented. Environmental friendly vehicles and their parameters have been characterized. The main decision problems in organizing the transport system, also in the context of the use of EFV, have been identified and analysed. Finally, an example of a model for assessing the efficiency of a transport system with an emphasis on its impact on the environment was presented. The article was concluded with the summary of considerations and the proposal for further work.

Schlüsselwörter

  • freight transport
  • external costs
  • Environmentally Friendly Vehicles
  • EFV
  • Multicriteria Decision Analysis
  • transport system effectiveness
Uneingeschränkter Zugang

Vibrodiagnostic of Welded Thin-Walled Plates with the Usage of Laser Sensors in Network Infrastructure

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 415 - 419

Zusammenfassung

Abstract

The article presents a non-destructive welded joints assessment (vibrodiagnostics) method, in which, with the use of the Internet, computer networking technologies and laser displacement sensors, the quality of welded steel plates may be monitored. The article also describes the possibilities of analysis of received vibrodiagnostics data on the base of diagnostic parameters analysed in function of time and frequency. The method described in the article allows remotely registering, analysing and diagnosing mechanical systems using vibrodiagnostics and information technologies. Modern, computerized methods exhibit efficiency and reliability of results – they are currently the best measuring tools that can be used in automatic monitoring (structural health monitoring - SHM) of marine structures. It is essential to make objective assessment of the results by NDT users, which is tightly connected with the expertise of norms and regulations of NDT. It may be helpful in this respect to monitor responses from a few sensors, arranged in a few measuring points. NDT results quite often trigger further analysis of durability of an object. The NDT of welded joints method as presented in the article allows remotely and in an IT-aided way analysing and diagnosing mechanical systems with the use of vibrodiagnostics method.

Schlüsselwörter

  • non-destructive testing
  • laser displacement sensors
  • NDT
  • vibrodiagnostic
  • Ethernet
  • LAN
Uneingeschränkter Zugang

Thermodynamic Analysis of Combustion Events in The Natural Gas Fuelled SI Engine With VVT

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 421 - 427

Zusammenfassung

Abstract

The main aim of the research was to investigate influence of overlap of the natural gas fuelled spark ignited engine on the following parameters: Indicated Mean Effective Pressure (IMEP), heat rate release including combustion phases (ignition lag, main combustion phase). The content of the study includes results from processing in-cylinder pressure measurements, heat release rate analysis, combustion phases, and finally the conclusions. The tests were carried out on the test bed including the single cylinder research engine with a displacement volume of 550 cm3. The engine was equipped with independent cam phasors for both intake and exhaust valves, but for this investigation, the exhaust valve timing was fixed (the exhaust cam centre line was fixed at -95 crank angle (CA) deg before Top Dead Centre) and intake valve timing was changed (the intake cam centre line was varied from 90 to 150 CA deg after Top Dead Centre). The overlap was changed in the range from 85 to 25 CA deg. 8 tests series were performed, each singular series consisted of 300 consecutive engine combustion cycles. As observed, by varying the valve overlap it contributes to significant change in the peak combustion pressure, peak of heat release rate, and combustion phases. Summing up, variable valve timing affects compression and expansion strokes by changing polytropic indexes due to various amounts of exhaust residuals trapped in the cylinder. It affects not only engine volumetric efficiency but also the heat release rate and IMEP, so it does engine performance. Thus, variable valve timing can be considered as valuable tool that can be applied to the natural gas fuelled internal combustion engine.

Schlüsselwörter

  • internal combustion engine
  • variable valve timing
  • heat release rate
  • IMEP
  • combustion phases
Uneingeschränkter Zugang

CFD Tests of the Exhaust System of a Sports Motorcycle

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 429 - 436

Zusammenfassung

Abstract

The content of this article describes the area of the operation of speedway racing motorcycles, it reflects the specific use, and thus, the special requirements placed on the internal combustion engines used there. Then, a research tool is presented in the form of Computational Fluid Dynamics methods. The article presents basic equations as a base for software, and emphasizes the essence and necessity of adequate selection of turbulence models. Presentation of the work tool is crowned with a brief description of the application in the form of Ansys numerical analysis software and a specific place and possibilities of its application. The practical part describes the work carried out during the tests of a GM 500 type combustion engine and attempts to compare two types of exhaust systems whose advantages and disadvantages in analytical calculations are difficult to determine, whereas CFD tests accurately represent pressure fields, velocities and the most important parameter in the form of resistance of the exhaust system. The article is crowned with the results of tests enabling determination and selection of the exhaust system with lower flow resistance and recommendations adjusting the exhaust system to a specific engine.

Schlüsselwörter

  • CFD
  • speedway
  • spark ignition engine
Uneingeschränkter Zugang

Planning and Building 100% Renewable Energy Infrastructure with the Technologies of the Future

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 437 - 445

Zusammenfassung

Abstract

When and why humanity faced the Energy Problem, it is a question. What was the problem? How are we trying to handle it since the beginning? Do we have enough resources of renewable energy? Which technologies are mature enough to contribute and take part in the solution? Are they available in the market with compatible prices? What is the role of storage for dealing with the intermittent nature of renewable energy resources? Why do we need to build, operate, integrate and manage energy efficiency, storage and renewable energy in harmony with nature by smart grids in sustainable cities of the future? Is transition to 100% Renewable Energy the solution? If so what else is required to reach this target? What are we going to do with the existing system? Which methodologies and techniques we need to use to realize this transition with minimum costs and externalities? How are we going to justify this transition? Is it only a technology problem? What parameters we need to consider when we are trying to live in harmony with nature? How are we going to readapt human beings to be satisfied with minimum ecological footprint societies? Can human beings build democratic societies where energy efficiency and 100% renewable energy is respected and beneficial for each individual of the communities? Transition to 100% renewables requires planning the future with the information of the future. For reaching this target we need to carry on a multidisciplinary approach to understand and take into consideration the basic constraints and requirements of the living space we are sharing all together in the atmosphere. How to Speed-up the Global Transition to 100% Renewable Energy?

Schlüsselwörter

  • energy
  • efficiency
  • transition to 100% renewable energy
  • energy storage
  • smart grids
  • planning future
  • future technologies
Uneingeschränkter Zugang

Innovative Composite Gyroplane Rotor Blades – Fatigue Tests

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 448 - 453

Zusammenfassung

Abstract

The paper presents test bench method for verifying the fatigue life of the rotor blades, working in operating conditions in a position steady flight (autorotation), on the aviation construction called the gyroplane. One of the critical elements of this design is the main rotor, which in its modern versions takes the form of advanced composite structures subjected to loads in flight complex variable, the nature of which differs from the well-known operating conditions of helicopter rotors. The article includes a description of the test object, which are composite rotor blades designed specifically to work in autorotation, the specificity of loads of autorotation rotor, and method of implementation of the gyroplane rotor work cycles in the test bench. The main aim of this research is to evaluate the sustainability of the composite blades under the gyroplane operating loads with the goal to allow the rotor to operate in the air. The tests were carried out for 100 hours of gyroplane flight at loads do not exceed the maximum operating loads, and for several hours under a load higher than operating. During test for the evaluation of composite structure, the infrared camera with dedicated software IRNDT was used. The reached showed structural integrity in critical mounting section of the blade.

Schlüsselwörter

  • rotor blades
  • fatigue tests
  • NDT
  • composite
Uneingeschränkter Zugang

Numerical Analysis of Residual Stress Distribution in Riveted Lap Joint Under Tension

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 455 - 462

Zusammenfassung

Abstract

Riveted joints are a common location of fatigue cracks in aircraft metal structures. Fatigue life of such joints as well as a place of cracks nucleation is strongly influence by a stress distribution in sheets, which is a result of residual stresses (mainly after riveting) and stresses induced by external loads. Stress distribution in two-row lap joint was investigated with the use of Finite Element Method. The joint consist of two 1.5 mm sheets and two protruding rivets with diameter equal to 4 mm, made of 2024 T3 (sheets) and 2117 T4 (rivets) aluminium alloys. The simulations covered a riveting process and tensile stages. The 3D models of joint with the universal rivets and with the brazier, rivets with a compensator were prepared. Elastoplastic material properties as well as geometric nonlinearity and contact phenomena were included. The results of simulations show that the residual stress distribution after release of tensile loading varies significantly from the distribution after riveting only. This fact should therefore be taken into account in a fatigue life estimation of such joints performed based on a FE calculation. The paper presents also the influence of the analysed rivet geometry on the stress distribution at the sheets faying surfaces.

Schlüsselwörter

  • joint
  • rivet
  • fatigue
  • residual stress
  • finite element
Uneingeschränkter Zugang

The Influence of Selected Adhesive Properties and the Manner of Surface Preparation upon Impact Strength of Block Adhesive Joints

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 463 - 469

Zusammenfassung

Abstract

The research described in this article is part of investigating impact strength in block adhesive joints. The authors checked experimentally the effect, on the test results, of the manner of surface preparation and compressive strength and Young’s modulus of an adhesive used to make the connection. The experimental testing was carried out with an impact pendulum tool, designed to examine adhesive joints. During such testing, the energy used to tear off the upper part of the specimen, that is the energy lost by the dropping device, is the measure of the impact strength of an adhesive connection. The elements of the samples were made with an aluminum alloy 2017A. In the investigations, the authors used non-normative samples whose upper element was a cylinder rather than a cuboid, as advised in the norm. The adhesive joints were made using epoxy adhesive Loctite, named EA 3421, or an adhesive composition Epidian 57 with Z1 hardener. The glued elements were prepared by treating the surfaces for bonding by means of the stream-abrasive processing. The abrasive mediums were three types of materials of different gradation. In addition, two series of samples were prepared using roughening by sandpaper. For control samples, the authors made joints, in which the surfaces for bonding became degreased merely by petroleum ether.

The results of the experimental studies indicate that the impact strength of adhesive joints is dependent on the manner of preparation of the bonded elements as well as on the longitudinal modulus of elasticity of the adhesive, which was used to make the connection.

Schlüsselwörter

  • adhesive joint
  • impact strength
  • adhesive properties
Uneingeschränkter Zugang

The Methods of Quality Assessment of the Tracked Suspensions of the Combat Vehicles

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 471 - 478

Zusammenfassung

Abstract

The extortions that result in the vibrations of a hull of the combat vehicle have an impact on the tracked combat vehicle during the off-road driving. They may have a negative impact on the crew, internal equipment, shooting accuracy. A level of the hull loads depends on quality of the suspension system, which main responsibility consists in minimising an amplitude of the vibrations. Therefore, it is necessary both to improve a structure of the suspension system, and its components, as well as their optimisation.

The tests of the driving smoothness of the vehicle and quality of the suspension elements can be realised both within a frame of the model tests and while driving in the real conditions. The assessment criteria of the driving smoothness are directly related to the negative influence of the vibrations to the human body. The suspension quality should be assumed both upon an execution of the vehicle prototype, and during the design or modernisation phase. It results both in reducing the time, and minimisation of the costs and risk related to the structure development. The model tests enable to evaluate the driving smoothness and comfort prior to an execution of the prototype. The tests on the test tracks in the final phase of the development are carried out in order to evaluate the driving smoothness.

Schlüsselwörter

  • tracked combat vehicle
  • suspension
  • driving smoothness
  • test track
Uneingeschränkter Zugang

The Application of Ant Algorithm in the Assignment Problem of Aircrafts to Stops Points on the Apron

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 479 - 487

Zusammenfassung

Abstract

The article refers to the problem of assigning the aircrafts to stops points on the apron. The aim of this paper is to develop the algorithm, which will be used to this assignment. The assignment problem of aircrafts to stops points is the complex decision problems, which refer to the problems of designating the minimal path in the graph. The assignment model was described, i.e. decision variables, constraints and the criterion function. Decision variables take the binary form and determine the connections between the elements of infrastructure of the apron, i.e. touchdown points, intermediate points and stop points. Constraints take into account the number of aircrafts in the given period, the number of unoccupied stop points. The criterion function determines the minimum driving time of the aircraft on the apron. In order to designate the routes in international transport the heuristic algorithm, i.e. ant algorithm was developed. The steps of building this algorithm were presented. This algorithm was verified in the C# programming language. The results generating by the presented algorithm were compared with the results generating by the random algorithm.

Schlüsselwörter

  • air transportation
  • air traffic control
  • aircraft operations
  • airport
Uneingeschränkter Zugang

The Car Fleet Management Model with Including Expectations of the Users

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 489 - 500

Zusammenfassung

Abstract

The paper presents a certain approach to fleet management in the company, taking into account the mobility of employees and the selection of vehicles for tasks. The main objective is to indicate the factors that significantly affect the proper selection of vehicles for the task, as well as concurrently meeting recipients' needs. The general model for fleet management was presented, taking into account not only the mobility of employees but also the method of obtaining funds for the replacement of greener cars. The current approach is based on the car purchase model in the form of credit, low-purchase leasing, and supervision over the use process and operating costs by the company's internal resources. The problem solved in the article concerns the analysis of entrusting fleet management to specialized Car Fleet Management (CFM) companies. It was pointed out that in this calculation model, CFM companies have to take into account many variables related to vehicle selection and mobility of employees in order to perform tasks. In this article, particular attention has been paid to the areas that CFM analyses when choosing a vehicle for a given company.

Schlüsselwörter

  • Car Fleet Management
  • assignment of vehicles to tasks
  • decision-making model of fleet management
Uneingeschränkter Zugang

Advantages of Compressor Downstream Air Partial Bleed and Supplying It Downstream of the Turbine in a Turbojet Engine

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 501 - 508

Zusammenfassung

Abstract

The research article discusses the advantages of using compressor downstream air partial bleed and supplying it downstream of the turbine, which was applied in a prototype of a “bypass” turbojet engine. The objective of such a turbo engine structural solution was discussed along with its elements and principle of operation. Further part of the article determines the impact of such partial air bleed on the value of achieved basic operating parameters of the engine, i.e., unit thrust and unit power consumption. The presented attempt to compare these parameters with the parameters achieved for a turbojet, single flow engine is very important; in the first case without air bleed, and in the second, with air bleed to the environment. Further sections of the article compared these parameters relative to a turbojet, turbofan engine with a jet mixer. Such comparisons enabled to determine the actual benefits of using compressor downstream air partial bleed and supplying it downstream of the turbine, which may constitute an intermediate solution between single flow turbine engines and turbo fan engines. Wide possibilities for the application of such structural solutions were shown, which was summarised in the conclusions.

Schlüsselwörter

  • aviation engine operating parameters
  • jet engine designs
  • aviation engine air bleed
Uneingeschränkter Zugang

Impact of Work of Turbine Adaptive Engines for the Natural Environment

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 509 - 516

Zusammenfassung

Abstract

The article describes the problem of the operation of turbine jet, adaptive engine work on the natural environment. In particular, the analysis of noise generated by turbine jet engines has been made. It points out possible directions of noise decrease with particular emphasis upon structural changes within the engines, the task of which is to reduce the noise mission. The example of the modernization is based upon the “bypass” type of one-flow turbine jet engine. The essay contains theoretical basis of calculation of the noise emission level and the results, which graphically indicate a relative level of noise of this type of engine depending upon the amount of discharged air and the diameter of the discharge nozzle and the radius, upon the basis of which the noise level is determined. This work also includes a comparison of the relative noise level of this type of engine with regard to one-flow turbine engine equipped with the function of air discharge to the environment and with regard to two-flow turbine jet engine equipped with air stream flow mixing device. The use of low-emission combustion chambers in the “bypass” turbine engine was indicated. This allowed addressing the problem of emissions of toxic exhaust components by this type of aircraft engines. At the same time, the dependence of this emission related to the mass of fuel used on the engine's thrust range was indicated. The article was concluded with a short summary.

Schlüsselwörter

  • noise of aircraft engines
  • the environmental impact of a jet engine turbine
  • emission of toxic compounds from aircraft engines
  • turbine jet engine
Uneingeschränkter Zugang

Selected Problems of Diagnosing Toothed Gears in the Aspect of Developing HUMS System

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 517 - 524

Zusammenfassung

Abstract

A diagnostic FDM-A method, based on the measurement of modulation of constituent frequency of direct current (DC) generator pulsation as well as FAM-C method, established on the measurement of frequency modulation of alternating current (AC) generator, were developed in the Air Force Institute of Technology [3, 9-10]. The essence of their accuracy lies in “natural” synchronizing of sampling with angular speed of the observed kinematic pair – if the dynamic processes of the observed object accelerate, the sampling becomes faster too [9-10]. At the same time, around the “synchronization points”, due to the clearance in the power transmission there is a certain natural oscillation between the observed kinematic pair and generator’s rotor − vibrations are created. These vibrations are called jitter [9, 23] and they constitute an additional supplement to this method, because they provide more information on resolution and accuracy. Moreover, the abovementioned method enables to define the level of subassembly abrasive wear and its location in the time of normal operation of the powerplant [9-10]. This method allows also detecting resonances of elements on the basis of observation of shape and relative position of characteristic sets, which i.e. enable to calculate the mechanical quality factor of kinematic pair − it is possible to establish the operation time of kinematic pair until entering the resonance degradation. Other numerous parameters associated with the assembly of power unit rotor were also outlined: rotor skew angle, level of frictional wear of bearing cage − lack of contact of bearing components, bearing assembly ovalisation.

Schlüsselwörter

  • aviation
  • alternator
  • frequency modulation
  • helicopter gearbox
  • bearing wear
  • gear wear
  • Health and Usage Monitoring System (HUMS)
  • power transmission
  • characteristic pattern
Uneingeschränkter Zugang

The Design and Simulation of an Automated De-Icing Control System in the Aircraft Diamond DA42