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 24 (2017): Heft 4 (December 2017)

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

Suche

49 Artikel
Uneingeschränkter Zugang

The Power Impact of Electric Power Assist in Hybrid Vehicle

Online veröffentlicht: 08 Nov 2019
Seitenbereich: 1 - 1

Zusammenfassung

Abstract

The current interest in the development of hybrid vehicles is a response to serious effects of road transport on the environment over recent years. In addition, vehicles equipped with this type of drive combine the advantages of a conventional diesel engine and electric motor. This results in higher system efficiency while reducing emissivity.

This work seeks to demonstrate the effect of electric power on the total power of a hybrid vehicle. The research on the chassis dynamometer (MAHA LPS 3000) of the hybrid sports car, Honda CRZ, has been performed in three modes of operation: normal, economical and sport. The obtained results are presented in the form of graphs of external engine characteristics, where the influence of electric power on the system is visible.

The tested vehicle is equipped with sixth version of Honda’s Integrated Motor Assist (IMA) technology, which is the crucial system, assisting the combustion engine in order to provide higher performance and better fuel economy.

Schlüsselwörter

  • hybrid vehicle
  • Honda CR-Z
  • electric motor
Uneingeschränkter Zugang

Electromagnetic Launcher Aviation Gun of the Future

Online veröffentlicht: 08 Nov 2019
Seitenbereich: 7 - 16

Zusammenfassung

Abstract

The electromagnetic rail launcher is a type of high-energy weapon that uses a strong magnetic field to project missiles. To create this field, a current pulse source is needed to provide sufficiently high voltages and currents. The study thoroughly examines the principle of electromagnetic operation of the rail launcher, with particular emphasis on how to achieve the highest electromagnetic field strength. The analysis has been subjected to the source of the impulse current and the tendency of their development in the near future. The subject of the appropriate rails selection and their mutual arrangement has been touched up to attain adequate strength against the harmful effects associated with the flow of high currents. Considerations have been taken to protect the rails from the harmful effects of large-scale current flows, and the topic of the projectile itself to the electromagnetic field was raised. The rapid development of technology over the last few years indicates that high-energy weapons will be the basic weapon of all types of forces in the near future. The development of electromagnetic railroads requires the solution of many mechanical problems and harmful phenomena.

Schlüsselwörter

  • electromagnetic rail launcher
  • electromagnetic railgun
  • electromagnetic field
  • magnetic field
  • pulse source
  • missiles
  • rails system
  • compulsator
  • magnetic materials
Uneingeschränkter Zugang

Energy State Impact on Friction and Wearing in Combustion Engines

Online veröffentlicht: 08 Nov 2019
Seitenbereich: 25 - 30

Zusammenfassung

Abstract

Friction pairs are designed from elements, where is very difficult to define in unequivocal way all optimal parameters. Research on stability of friction pairs are focused on the surface and the top layer of surface in the parts. The main goal is find new solutions to design and material, thereby achieving one million kilometres of mileage to main repair in the case of internal combustion engines. The biggest structural difficulties are noticeable in friction pairs where we can observe sliding and returning motion, which is also connected with sealing function. Piston – ring – cylinder assembly of combustion engine has many friction pair’s examples, also one of them, which decide about fastness to wear. A typical example of such a pair is first sealing ring – cylinder sleeve, called further in piston – rings – cylinder unit in combustion engine. Engineers are currently seeking an additional factor, which would be unable to gain the reduction of tangential force by reducing the friction coefficient in elements of friction pair during operations. Such a factor may be the surface free energy that results from molecular structure and nature of the bonds between the molecules present in the material. Components of surface free energy determine the tribological properties of the material, which is reflected in the stability of the units. The work aims to show the possibilities and benefits of the application of this new method in order to reduce wearing, which is consistent with the observed trend of technology development.

Schlüsselwörter

  • friction
  • energy state
  • combustion engines
  • wetting drop
  • tribology
Uneingeschränkter Zugang

Dynamic Weighing System Used in Excavator

Online veröffentlicht: 08 Nov 2019
Seitenbereich: 31 - 38

Zusammenfassung

Abstract

In many industrial applications is taken to consider change of payload potential energy while lifting it. It allows obtained directly benefits. For example, the cost of material loaded on a dump truck in a composition of coal is generally priced by its weight. In this case, the truck has to pass a stationary scale twice to identify its payload, before and after loading. Measuring weight of the material instantly while loading the truck, increases the efficiency of the process and makes a stationary scale unnecessary. In addition, it is possible to prevent overloading of means of transport, which use public roads, and can be weighed by the road service. The typical solutions of the static and dynamic weighing system from market were compared. The theoretical model is presented basing on geometrical and mass parameters of excavator CAT 301.5. The weighing system used in off-road machines is usually based on the measurement of the working fluid pressure in the piston chambers of the hydraulic cylinders, which lift the machine work equipment together with a payload. In this article is shown a solution with load pin, which allows the determination of the load mass independently of the several factors affecting the classic weighing system. The possibility of payload mass measuring on the excavator was estimated during tests on prepared research stand. There were obtained a good agreement of experimental research results with the mathematical model.

Schlüsselwörter

  • weighing
  • excavator
  • load pin
  • pressure
  • pay load
Uneingeschränkter Zugang

Comparative Analysis of the Operating Indexes of Manually and Automatically Controlled Passenger Car Powertrain System at Variable Load States

Online veröffentlicht: 08 Nov 2019
Seitenbereich: 39 - 46

Zusammenfassung

Abstract

This article reports the results of a study into operating parameters of a system consisting of an SI engine and a powertrain in a Fiat Panda passenger car in the conditions of a variable load. The analysis was primarily concerned with the variability of fuel consumption resulting of the changing load applied to the driving wheels in the conditions of a test performed on chassis dynamometer for manual and automatic controlled transmission gear change The test bench included a dedicated driving cycle, which was developed as cycle with periodically changed constant linear speed of the car every 10 km/h. According to the vehicle set speed, the load on its wheels was determined by the basic resistance as rolling resistance, air resistance and resistance corresponding to road inclination. Each period of a drive cycle corresponding to steady state driving gave the average instantaneous values of drive system performance indicators. The waveforms of these indicators were recorded and then averaged and presented as representative points of the powertrain system that were analysed. The focus of the study involved the identification of the points characterized with the minimum specific fuel consumption and impact of type of powertrain control on emission of CO2 from passenger car SI engines.

Schlüsselwörter

  • fuel consumption
  • spark ignition engine
  • variable load
  • engine efficiency
  • motion resistance
Uneingeschränkter Zugang

Semi-Markov Model of Multi-Modal Transport Operation

Online veröffentlicht: 08 Nov 2019
Seitenbereich: 47 - 54

Zusammenfassung

Abstract

Multi-modal transport means the transport of the objects through at least two different carriers of any combination of simple tasks of transport carriers (by truck, by train, by ship or by plane). A Semi-Markov (SM) model of multi-modal transport operation is presented in the article. The SM process is defined by the renewal kernel of that one. In our model, time to failure of the operation is represented by a random variable that denotes the first passage time from the given state to the subset of states. The duration of one operation cycle is a random variable representing the return time to the initial state. The appropriate theorems of the Semi-Markov processes theory allow us to calculate characteristics and parameters of the transport operation model.

The article presents the example of the transport operation final part of container with cargo from Warsaw to Stockholm, where from Warsaw to Gdynia, the container is transported by lorry, from Gdynia to Karlscorona by ferry and from Karlscorona to Stockholm by truck.

Schlüsselwörter

  • Semi-Markov model
  • multistage transport operation
  • reliability function
  • mean time to failure
Uneingeschränkter Zugang

The Assessment of Surface Layers Texture of the Fouling Gathered on the Heat Transfer Surfaces within Regenerative Feedwater Heat Exchangers

Online veröffentlicht: 08 Nov 2019
Seitenbereich: 55 - 60

Zusammenfassung

Abstract

The fouling presence on the heat transfer surfaces, both on the waterside and the steam side of the steam power plants heat recovery exchangers usually leads to the loss of their heat transfer capacities. This loss appears owing to the high value of heat resistance of fouling. Furthermore, these deposits are most often formed with irregularities in the surface layers. These textures are usually characterized by a varied, often stochastic and difficult to define, geometric structures. The most common measure of their inequalities is the roughness parameter describing the surface geometry. The fouling surface layer texture can, on one hand, cause enhancement of the heat transfer process, but on the other hand, it may contribute to an additional increase in thermal degradation of the heat exchanger. Many experimental studies have shown that the greater the unevenness of the heat transfer surface on the waterside of a given heat transfer device, the smaller increase in the thermal resistance of the impurities over time, thereby increasing the amount of heat transferred. It should be emphasized, however, that the rise in roughness results in an increase in the heat transfer coefficient, while simultaneously intensifying the flow resistance of the working medium. Taking into account the heat transfer surface by steam side, the increase in the roughness promotes the formation of a thicker condensate layer, thus impairing the condensate drainage organization. It can be explained by the fact that deposits settle in a sort of quasi-rib effect, although with undefined ribbed grid, it may lead to the overflow of inter-finned passages. The article shows the previously mentioned phenomena and also presents the descriptive quantities for the fouling surface layer texture, based on the results of the author’s own experimental research.

Schlüsselwörter

  • steam power plants
  • heat recovery devices
  • fouling
  • surface layer texture
Uneingeschränkter Zugang

Description of the Pneumatic Work Cycle of the Starting Unit of the UAV Launcher

Online veröffentlicht: 08 Nov 2019
Seitenbereich: 61 - 70

Zusammenfassung

Abstract

The publication presents a UAV pneumatic launcher designed and built in ITWL. The basic element of the pneumatic launcher is the launch mechanism. The starting mechanism determines the energy parameters that will be reached on the launch pad. The work of the launch engines used in propulsion systems has been reviewed and their advantages and disadvantages are discussed when used in pneumatic launchers. A detailed description of the author’s solution of the pneumatic launching mechanism from the launcher is presented. In order to determine guidelines for the design of pneumatic starter systems, a description of the cycle of operation of the complex pneumatic system was analysed. The description of the pneumatic system’s work cycle was based on the parameters of the flow of the compressed air C and b (C – the sound conductivity of the pneumatic element, b – the critical pressure of the pneumatic element). A set of equations describing the pressure change in the filled and emptied valve compartment and the equation of motion are presented. The equations of a mathematical model describing the pneumatic component and the replacement value of flow parameters for the pneumatic system of series pneumatic components are presented. For the mathematical model, a calculation algorithm is presented which takes into account the initial conditions and the boundary conditions of the various periods of the pneumatic system cycle. Examples of calculation results for a specific pneumatic trigger mechanism are shown. The results obtained were compared with the results of the pneumatic starter station tests and the mathematical model of the pneumatic starter was evaluated.

Schlüsselwörter

  • launcher
  • pneumatic trigger
  • pneumatic system
Uneingeschränkter Zugang

Project Zeus: Video Based Behavioural Modelling of Non-Linear Transportation System for Improved Planning &Urban Construction Projects

Online veröffentlicht: 08 Nov 2019
Seitenbereich: 71 - 81

Zusammenfassung

Abstract

The ability to analyse the traffic and urban mobility pattern with the help of video analytics, which occur in massive volumes of surveillance video will lead us to provide a knowledge based for the urban planners and policy makers to come up with better construction planning. This will soothe the needs of urban commuters and thereby saving unnecessary spillage of money on the construction projects. In this research project, we present an artificial intelligence framework for transport video analytic; which autonomously models behavioural patterns of commuters and flow of traffic, wherein it taxonomically classifies essential patterns based on geometrical feature points of interest to facilitate reality mining. This behavioural pattern of commuter and traffic flow can later be queried and fetched through the newly mathematically programmed ontological data warehousing module, where such reality mined contextual data could be used for sharing essential data.

Schlüsselwörter

  • Algorithms
  • computer vision
  • traffic activity recognition
  • event detection
  • activity analysis
  • behaviour modelling
Uneingeschränkter Zugang

Method of Preliminary Evaluation of Biocomponents Influence on the Process of Biofuels Combustion in Aviation Turbine Engines

Online veröffentlicht: 08 Nov 2019
Seitenbereich: 83 - 90

Zusammenfassung

Abstract

The aim of this article is presentation of the new method of preliminary evaluation of biocomponents influence on the process of biofuels combustion in aviation turbine engines. This method is based on the tests of evaluated biofuels on engine stand MiniJetRig equipped with small turbine engine. The idea of this new method is to compare the combustion process of evaluated biofuel with the combustion of reference fuels. The reference fuel used in presented research was mineral Jet A1. Two compositions of pure hydrocarbons were blended with Jet A1 fuel and tested using MiniJetRig. The main criterion of combustion process assessment was CO concentration in exhaust gases. As the final criterion of evaluated biofuel the ∆CO = [COWx – COJet] was adopted, where COWx – the concentration of CO in exhaust gases emitted during combustion of evaluated fuel and COJet – the concentration of CO in exhaust gases emitted during combustion of Jet A1 fuel. This method was preliminary verified using HEFA biofuel previously accepted for aviation application. The obtained results qualify this biofuel as similar to Jet A1 ones – the DCO was within limits –30 – +20. The presented method needs further research, using much more evaluated fuels, to confirm their usefulness for laboratory pre-selection of new biofuels.

Schlüsselwörter

  • Fuels for aviation turbine engines
  • biofuels
  • synthetic hydrocarbons
  • engine tests
Uneingeschränkter Zugang

Theoretical and Experimental Investigation of a Ground Resonance Phenomenon for the ILX-27 UAV Helicopter

Online veröffentlicht: 08 Nov 2019
Seitenbereich: 91 - 98

Zusammenfassung

Abstract

Ground resonance is an unbalance of the helicopter main rotor rotation caused by its asymmetry. Whilst the helicopter is in contact with the ground this asymmetry generates a divergent and often destructive oscillations of the helicopter structure. These oscillations are self-excited. This paper present results of both theoretical and experimental investigations of this phenomenon. They were dedicated to the new polish UAV helicopter ILX-27. The theoretical analysis were done with commercial software ANSYS using Finite Element Method. The virtual model of the helicopter model accurately reproduced the geometry of all elements of the helicopter and was easy to modify to simulate various kinds of damages. Calculations were done for the following cases: C1 – the helicopter standing on the ground with zero thrust of the rotor, C2 = C1 + helicopter with additional support of the rotor mast, C3 = C2 + thrust of the rotor equal to the total mass of the helicopter, C4 = C2 + fixing the helicopter to the ground, C5 = C2 + helicopter with additional mass. At the beginning the modal analysis for all cases was done – natural frequencies and modes of the structure were identified. Next, for selected cases, harmonic analysis was performed – the structure of the helicopter was loaded with concentrated harmonic forces. Finally the dynamic analysis gave time courses of blades and the hub center motions in the case of structural damages. All phases of simulations were correlated with ground tests of the helicopter prototype. This allowed to compare results of theoretical investigations. These results also supported tests of the prototype.

Schlüsselwörter

  • ground resonance
  • dynamics of helicopter structure
  • finite element method
  • simulation
  • ground tests
Uneingeschränkter Zugang

Research Performance of Novel Design of Diesel Engine

Online veröffentlicht: 08 Nov 2019
Seitenbereich: 99 - 108

Zusammenfassung

Abstract

Certain results of the comparative studies of the high-speed Diesel engine V-12 of the “W” series were presented in the article. The engine was modernised in regard of possibilities to achieve better performances at specific fuel consumption, smaller exhaust emission, smaller scavenge, lower noise and better thermal stability. The subject of this work is the piston cast of novel composite silumin. The development of novel composite silumin (aluminium-silicon alloy), which contains a little more Copper and Nickel, and the introduction of novel alloyed elements, such as Chromium, Molybdenum, Tungsten, increases the strength of the alloy and its thermal stability during successive heating and cooling. The pistons made of this alloy may have a little bigger outside diameter than the pistons made of PA-12 standard alloy, and a smaller clearance between the piston and cylinder liner. The pistons made of standard and novel alloy were mounted successively in the “W” engine. The full load and part load curves were determined. The lubrication oil consumption, fuel consumption, exhaust emission, blow-by and noise were determined too. The article presents the results of the above-mentioned research. The novel composite alloy enables further engine modernization because the engine should operate at higher pressure and temperature in the combustion chamber.

Schlüsselwörter

  • internal combustion engine
  • Diesel engine
  • engine piston
  • composite alloy
  • thermal stability
Uneingeschränkter Zugang

Properties of Novel Composite Alloys Used for the Engine Pistons

Online veröffentlicht: 08 Nov 2019
Seitenbereich: 109 - 116

Zusammenfassung

Abstract

The article presents the results of the investigations cover novel composite silumins with new alloying additives, such as chromium and molybdenum (not yet used in this type of silumin) and increased content of nickel and copper. The samples strength tests were performed at room temperature (20°C) and at elevated temperatures (up to 350°C), and were carried out using the strength machine, equipped with the special climate chamber. The dimensional stability of the new aluminum alloy was investigated using the precision dilatometer. This device allows one to register and record the sample dimensions as a function of temperature, during sample heating and cooling. During the DTA crystallization process investigations, derivative curves have been determined, that allows the analysis of the solidification process and the analysis of the heat transfer process in the sample structure and phase transformations. In the article shows the derivative curve and representative microstructures, and characteristic temperatures for the conventional AlSi12 alloy and novel composite alloy. All research results indicated that the newly developed composite aluminum alloy has far better parameters than aluminum alloys used previously for pistons of the internal combustion engines.

This article concludes with a summary of the advantages of the new composite alloys.

Schlüsselwörter

  • novel composite alloys
  • the engine pistons
  • thermal derivative analysis
Uneingeschränkter Zugang

Verification of the Precise Position of the Aircraft in Air Navigation Based on the Solution of the RTK-OTF Technique

Online veröffentlicht: 08 Nov 2019
Seitenbereich: 117 - 124

Zusammenfassung

Abstract

The article presents the possibility of applying the differential technique RTK-OTF to recover the position of the aircraft in the post-processing mode. Within the framework of the conducted research, the authors designated the geocentric coordinates XYZ of the aircraft and compared them. In the research experiment, they used archive materials from the test flight of the aircraft Cessna 172 around the airfield in Deblin on 1 June 2010. The actual position of the aircraft Cessna 172 was recovered on the basis of GPS kinematic observations registered by the receiver Topcon HiperPro mounted on board the aircraft. In the calculations, the authors also used static GPS observations from the reference station REF1 as well as virtual reference stations VirA and VirB. The final coordinates of the aircraft Cessna 172 with three independent determinations RTK-OTF were defined in the AOSS v.2.0 programme. On this basis, they made verification of accuracy in determining XYZ coordinates of the aircraft Cessna 172. The dispersion of results for the difference in the designation of the X coordinate of the aircraft ranges from –0.19 m to +0.05 m. On the other hand, the size of the difference in the designation of Y-coordinate of the aircraft ranges from –0.07 m to +0.11 m. In addition, the dispersion of the results for the difference in the designation of the Z coordinate of the aircraft is from 0.19 m to +0.12 m.

Schlüsselwörter

  • GPS
  • RTK-OTF
  • accuracy
  • air navigation
  • RMS
Uneingeschränkter Zugang

Fuzzy-Lyapunov Based Controller for a Quadrocopter

Online veröffentlicht: 08 Nov 2019
Seitenbereich: 125 - 132

Zusammenfassung

Abstract

Quadrocopters are nonlinear and inherently unstable systems. To be able to account for the nonlinearities during more aggressive manoeuvres nonlinear control methods need to be utilized to obtain the desired position while at the same time guaranteeing stability. In the article, the quadrocopter dynamics is modelled using the Newton-Euler method. The propeller aerodynamics is modelled using a combination of momentum theory and blade element theory. There are two different control objectives; the 1st objective requires the quadrocopter to reach a desired attitude set point using, while the 2nd objective requires the quadrocopter to track an attitude trajectory. In both cases, Lyapunov stability criterion, in conjunction with LaSalle’s invariance principle, is used to guarantee the system becomes asymptotically stable. In the case of reaching the desired attitude set point, a direct Lyapunov control method is implemented with the control constants determined empirically. For the trajectory tracking, limited knowledge is assumed on the system dynamics and the Mamdani fuzzy controller is used with a rule base that satisfy the Lyapunov stability criterion. The fuzzy membership functions developed empirically and a centre of gravity defuzzification method is used. All simulations are done in MATLAB/Simulink. The results of the numerical simulation are presented in the article.

Schlüsselwörter

  • quadrocopter
  • fuzzy control
  • Lyapunov stability
Uneingeschränkter Zugang

The Influence of Changing of Cutting Parameters on Temperature and Cutting Forces During Turning Process of Stainless Steel With CCET09T302R-MF Insert

Online veröffentlicht: 08 Nov 2019
Seitenbereich: 133 - 140

Zusammenfassung

Abstract

One of the greatest problems of modern production techniques is the achievement of an appropriate quality at minimal costs and accompanied by the production efficiency increase. Therefore, while designing the production process, the technology used should have a considerable influence on the durability and reliability of machine parts to be produced. During finish treatment, the final dimensions as well as functional properties are imparted to a given element by application of proper treatment type. The engineer has a range of production techniques to choose for the proper surface layer formation. It is crucial to find a suitable solution which will meet the requirements as well as the work conditions of a given machine part. The article presents the results of influence of change of cutting parameters on temperature and cutting forces during turning process of stainless steel. A shaft made of 304L stainless steel was used for the research. The cutting process was carried out on a universal CDS 6250 BX-1000 centre lathes. Measurement of cutting forces during lathing process used DKM 2010 turning dynamometer. The turning process was conducted by a cutting tool with CCET09T302R-MF insert by DIJET. During the turning, the following machining parameters were used: cutting speed Vc = 226 m/min, feed f = 0.044, 0.062, 0.083, 0.106 mm/rev and cutting depth ap = 0.25, 0.5, 0.75, 1.0 mm. The chemical composition of steel was measured by Solaris-ccd plus optical spectrometer.

Schlüsselwörter

  • turning dynamometer
  • temperature and cutting forces
  • stainless steel
Uneingeschränkter Zugang

Semi-Markov Model of Quality State Changes of a Selected Transport System

Online veröffentlicht: 08 Nov 2019
Seitenbereich: 141 - 148

Zusammenfassung

Abstract

The study deals with the problems connected with evaluation and analysis of transport systems operational quality. The research object is a real, sociotechnical system (of the type H-M-E) whose functional quality is affected by: operators, equipment and technical state of he operated vehicles and the environmental impact. A scheme of an assessment model was built on the basis of a developed concept of a system operational quality and a random process was defined to be used for the analysis. The assessment process involves investigating the variability degree of properties included in the resultant model in a given time and determining whether and to what degree the obtained values meet the requirements of the system appropriate operational quality. On the basis of the above assumptions and in result of experimental tests, four qualitative states of a transport system functioning, which represent intervals of values of the obtained grades in given time moments, were distinguished. The study presents a model of system operation qualitative state changes developed with the use of Markov chain inserted into a certain semi-Markov process. A graph and a matrix for probability of transition between the states were created and boundary distributions of the process were determined on the basis of experimentally obtained data. A system of equations was determined for the distinguished Markov chain, on the basis of which a mathematical model for assessment and control of operational quality of selected types of transport systems will be built.

Schlüsselwörter

  • transport system
  • efficiency
  • operation and maintenance process
  • semi-Markov process
  • simulation tests
Uneingeschränkter Zugang

Simulation Studies of Hybrid Powertrain for Urban Vehicles

Online veröffentlicht: 08 Nov 2019
Seitenbereich: 149 - 156

Zusammenfassung

Abstract

The powertrain of an urban vehicle was subjected to detailed simulations. This study was conducted with the aim of getting to know the operating principle, verification of assumptions adopted during its design and determination of most effective control procedures to be applied with regard to its powertrain. However, the most important aspect involved the aspect of the power distribution between the engines, electrical machine and vehicle wheels in the particular operating modes of the powertrain. A study was conducted in the MATLAB/Simulink environment with the purpose of finding a configuration of an electrical machine coupling with a combustion engine that offers the greatest advantages in terms of the range of the speed ratio, demanded performance of the electrical machine and maximum power output. The simulations indicated that control of the speed ratio of the vehicle could be gained by application of an electrically controlled planetary gear. The range of the transmission ratio is relative to the ratio of the planetary gear, speed range of the combustion engine as well as electrical machine. The efficiency of the battery charging in the hybrid mode is mostly relative to the operating point of the engine. The optimization of the process of power generation by the electrical machine requires that the operating point of the engine be maintained at a range at which its high performance is guaranteed.

Schlüsselwörter

  • hybrid drive
  • electrically controlled planetary gear
  • integrated control
Uneingeschränkter Zugang

The Study on Algorithm for Identification the Fatigue Crack Length of Compressor Blade Based on Amplitude-Frequency Resonant Characteristics

Online veröffentlicht: 08 Nov 2019
Seitenbereich: 157 - 164

Zusammenfassung

Abstract

The article is focused on building the algorithm for identification the fatigue crack length in the first stage of compressor blade of the helicopter PZL-10W turbo-shaft engine. The fatigue wear of compressor blade is a process in which the fatigue crack begins at the structural notch of the working part. For compressor blade, the crack starts at the leading edge and progress along the blade chord. Due to working conditions, the compressor blades are referred to as critical components. The helicopter rotor downwash can easily lift particles form the ground that may cause damages in the compressor section. Aircraft engines are designed so that the rotational speed of impeller remains below the resonant frequency. However, the pulsation of working medium or mechanical vibrations may cause temporary increase of vibration frequency. The appearance of structural notch combined with temporary increase of vibrations may initiate the fatigue failure. The works undertaken at the Department of Aircraft and Aircraft Engines, Rzeszow University of Technology provided a wide spectrum of research data of amplitude-frequency (A-F) characteristics of 1st stage of compressor blade. For different crack lengths, the fatigue tests of resonant frequency and asymmetry of A-F characteristics were acquired. The crack lengths were measured by fluorescent or infrared mapping method. The aim of the article is to develop the numerical method for identification of crack length of compressor blade basing on A-F characteristics. The studies on A-F characteristics in order to find correlations between crack length, resonant frequency and characteristics asymmetry were performed. The next step was to build the algorithm for identification the crack length when only A-F characteristic is known. The article contains the description of researches background, A-F characteristics unique features, algorithm detailed methods of work and sample use of algorithm in identification the crack length.

Schlüsselwörter

  • fatigue failure
  • crack length
  • compressor blade
  • aircraft engine
  • failure identification algorithm
Uneingeschränkter Zugang

Automation of Training Methods and Judging of Aerobatic Flights

Online veröffentlicht: 08 Nov 2019
Seitenbereich: 165 - 171

Zusammenfassung

Abstract

The article presents the specificity of aerobatic operations that use on-board transmitters to improve the quality of training and judging in this sport area. The first chapter of this work is an introduction to the topic under discussion and the second chapter describes the principles of aerobatic competitions, methods of judge evaluations and the regulations related to the correctness of the figure performance by the pilots. The third chapter contains information on the AeroSafetyShow Demonstrator+PL system (ASSD+PL) used to carry out active supervision over flights in general aviation (especially in gliders and airplanes aerobatic). In the fourth chapter of the article, the possibilities of application of the ASSD+PL system functionalities were described which could improve the quality of training and judge evaluations. The Polish measurement system is actually an only electronic system, which is accepted and respected by the aerobatic judges all over the Europe. Functionalities of the ASSD+PL are used by them to control and sum up all the forbidden crosses the box. The pilot flying too low can be even disqualified. Application interface can be also transmitted in the real time to the big screen as well for the judges, as for the wide spectators watching the competitions flights.

Schlüsselwörter

  • aerobatics
  • aerobatic training
  • aerobatic judging
  • on-board transmitters
  • supervision system
Uneingeschränkter Zugang

The Fourier Transform as a New Approach of Evaluating the Internal Combustion Engine Indicator Diagram

Online veröffentlicht: 08 Nov 2019
Seitenbereich: 173 - 180

Zusammenfassung

Abstract

In this paper, the authors present an introduction to the new method of evaluating the indicator diagram of internal combustion engine. For several years, it was observed that analyses of combustion processes have been hardly changed since they were conducted for the first time. At the moment, the diagrams are plotted more and more precisely owing to the new sensors and digital processors. Despite all of these high technical advantages, which were obviously unavailable in the past, theoretical approach for describing indicator diagram has not changed in significant way. Nowadays, the indicator diagrams are still evaluated very generally and are presented in much too idealistic way as a smooth curve of pressure changes, without any disturbances, which are being detected very easily now. Furthermore, it appears that performance improvements of the IC engines are in need of developing new methods for analysis and evaluation. The Fourier transform is a new way to look at the combustion process in the engines. It is basically a mathematical instrument for analysing different types of signals, which are transformed, from time domain into frequency domain. It enables identifying specific sinusoidal components of arbitrary signals and separates relevant ones from the noise. This allows one to see significant differences in two or more apparently similar signals and detect the crucial parts. If we treat pressure changes in time like a common signal, we can compute Fourier transform and see basic components of the diagram.

Schlüsselwörter

  • indicator diagram
  • Fourier transform
  • internal combustion engine
Uneingeschränkter Zugang

Testing of Internal Combustion Engines of Motorcycles with the Use of Thermal Imaging Methods

Online veröffentlicht: 08 Nov 2019
Seitenbereich: 181 - 186

Zusammenfassung

Abstract

The internal combustion engine should be rated for the thermal loads that come from different sources. Thermal analysis is important both for design purposes and for evaluating the conditions of its use. Very good results are obtained by a combination of non-invasive measurement techniques, such as research using infrared thermal imaging techniques [3, 11]. The purpose of the study was to determine the engine thermal load by evaluating the average temperature on the outside surface of the engine at many of its points for two selected motorcycle engines with similar displacement capacities.

For many reasons, such as ecology, durability, engine strength and thermal performance when heating and cooling are critical. To accomplish this task, a thermographic technique for indirect evaluation has been used, thus creating the possibility of measuring the temperature in a dynamic manner. These are accurate measurements and most importantly do not interfere with the construction of the object under investigation. The engine was tested during operation according to external and load characteristics. As a result of the work, graphs of temperature curves of heating and cooling of the tested engines were compiled. The article presents a methodology for measuring the temperature fields of outer surface engines. The collected material will be used in the future for studying the equable load on the cylinders, and as accurately as possible determine the conditions of movement such as power, revolutions, flow rates, temperatures and pressures.

Schlüsselwörter

  • combustion engine
  • thermal analysis
  • thermography
  • thermal research of motorcycles
Uneingeschränkter Zugang

Assessment of the Suitability of the Fuels with Component Power Engines

Online veröffentlicht: 08 Nov 2019
Seitenbereich: 187 - 192

Zusammenfassung

Abstract

The article presents the results of laboratory tests of selected properties of fuels available on the market and fuels with higher density component B100 obtained from rapeseed oil (10, 30, 50 and 100%). An analysis of the cetane number, viscosity, and weight of the ash remaining after combustion of fuel samples was made. It was found that the cetane number of pure biocomponent is higher than diesel oil of mineral origin and it slowly decreased along with a decrease in the Extras component. All tested samples of fuels have appropriate cetane number to power internal combustion engines with compression ignition. The viscosity of the fuel samples measured at a temperature of 30ºC increased along with an increase in the content of biocomponent and approached the limit values for fuels. According to the results presented by other authors in their studies ash mass decreased along with an increase in the content of the component. Only premium diesel showed less ash mass than other fuel. The study includes also the energy value and the calorific value of liquid fuels with addition of a biocomponent, which power diesel engines. The results of the tests indicate a slight decrease in the calorific value of the fuel along with an increase in the content of biocomponent, which does not affect the ability to power the engines. Laboratory tests have proved that use of methyl esters of fatty acids in diesel fuel is the right choice to power diesel engines.

Schlüsselwörter

  • transport
  • biocomponent
  • diesel
  • energy
  • calorific value
  • viscosity
  • cetane number
Uneingeschränkter Zugang

Assessment Method of End-of-Life Vehicles Recycling Network Efficiency

Online veröffentlicht: 08 Nov 2019
Seitenbereich: 193 - 201

Zusammenfassung

Abstract

Recycling is a final stage closing the life cycle of vehicles. The quality of this process affects the combined impact of automobiles on the environment. Recycling networks differ in the level of efficiency due to the differences in how the recycling system is organized, their environment, and the characteristics of the entities taking part in recycling process. The article presents an algorithm of a method for assessing the effectiveness of a vehicle-recycling network, which can be used in a comparative analysis of networks, or for evaluating changes over time. A set of indicators relating to the technical, economic, environmental, and social aspects was proposed.

The article presents the variety of aspects involved in assessing, the efficiency of a vehicle-recycling network the best solution seems to be the inclusion of selected indicators for the assessment model, which will also act as a tool to assess the state of the network and conduct rankings of available solutions. The model for assessing the efficiency has to be preceded by determining the purpose and scope of the assessment and analysis of available evaluation tools.

Schlüsselwörter

  • recycling network
  • end-of-life vehicles
  • system efficiency
  • indicators
Uneingeschränkter Zugang

Diagnostic of the Piston Rod Gland’s Failure of Marine Slow Speed Main Engine

Online veröffentlicht: 08 Nov 2019
Seitenbereich: 203 - 210

Zusammenfassung

Abstract

The article presents untypical diagnostic of the slow-speed, marine main engine. The engine was newly made-up and checking during mounting process and during sea trial. However, a leak under piston chamber of second cylinder along the piston rod appeared few days after the sea trial. The stuffing box exchange (with the piston rod’s regeneration) did not give expected results − the failure happened again. All geometrical and exploitation parameters was in acceptable range. The ship with main engine was fifth in the series of sister ships. The authors were asked for urgent expert opinion. Mix of different measurements was planned after formulation several hypothesis. Displacements of piston rod and cylinder, a stress level of main engine body, and vibrations level in different points of main engine was performed during short sea voyage. Not a single hypothesis can be considered as the main cause of the failure. It turns out, that a serious failure need not be caused by a single reason. According to snowball theory a sum of small effects, each of them affecting slightly the engine operation, can be a cause of serious failure. In the authors’ opinion, the failure was caused by a sum of relatively slight effects. The probably scenario of the failure process was enunciated. The recommendation for the engine project was formulated: some of the geometrical tolerances should be changed.

Schlüsselwörter

  • marine propulsion systems
  • slow-speed main engine
  • failure of piston-crankshaft system
  • diagnostic based on vibrations
  • displacements and stresses level
Uneingeschränkter Zugang

Using Fuzzy Logic Expert System for the Estimation of the Probability of Armour Penetration by PGU-14 Shells Fired from the GAU-8/A Cannon

Online veröffentlicht: 08 Nov 2019
Seitenbereich: 211 - 218

Zusammenfassung

Abstract

The article discusses the possibility of armour penetration by PGU 14 API shells fired from the GAU-8/A cannon. The considerations focus on questions with regard to the probability of armour penetration with the initially established conditions in the project. In the analysis, the authors took into account three parameters: armour thickness, armour slope and target distance. Based on the initial parameters, the authors estimated the probability of armour penetration. The designed a fuzzy expert system in the MATLAB software as well as conducting simulation of its performance in the Simulink programmes. The authors presented the performance of the system based on twenty samples for research, which simulate different thickness of the target armour, different distance from the target and different slope of the armour. The authors presented control surfaces, due to which it is possible to analyse the system performance. They also show the simulation process in the Simulink software package with the preset values. On the basis of the created controller, it is clear that a well-developed system, which had undergone testing and optimization, is capable of calculating near reality probability values. The designed system might improve fire effectiveness of ground targets during air training and combat tasks, as well as optimizing the consumption of air-to-ground armour piercing (AP) shells.

Schlüsselwörter

  • fuzzy logic
  • fuzzy expert system
  • armour penetration
  • GAU-8/A cannon
  • PGU 14 API shells
Uneingeschränkter Zugang

Influence of Effectiveness Speed in Mechanical Properties of AW6060 T66 (PA38) Alloy

Online veröffentlicht: 08 Nov 2019
Seitenbereich: 219 - 226

Zusammenfassung

Abstract

The article examines the effect of the change in the speed of deformation on the mechanical properties of AW 6060 alloy specimens, characterized by high mechanical strength, which is a material used in the shipbuilding industry. The theoretical basis for the influence of load speed on the mechanical properties of materials is presented. Static and dynamic tensile test was conducted on a universal testing machine. Dynamic stretching was performed on samples at 10−1 s−1 – 102 s−1. Done charts and tables showing results. Calculated in accordance with DIN EN ISO 6892-1 2010P total elongation and contraction of the sample. Comparison of the results of the study with the current knowledge of the subject. Material studies have shown that increasing the deformation rate results in an increase in the yield point and tensile strength. On the basis of calculations of the narrowing and elongation of the total sample, the material can be strengthened. The rate of deformation of the materials is favourable for their strengthening by increasing the limit of tensile strength. Given that most of the design is subject to dynamic loads and the aluminum alloy AW 6060 finds extensive use in shipbuilding and beyond, these are satisfactory results.

Schlüsselwörter

  • alloy aluminum
  • static load
  • dynamic load
  • yield strength
  • strength limit
Uneingeschränkter Zugang

Modelling of the Influence of Tire Characteristics on Stability of Motion with Using Vehicle at a Scale

Online veröffentlicht: 08 Nov 2019
Seitenbereich: 227 - 237

Zusammenfassung

Abstract

The use of physical models of vehicles, at a scale allows them to be used when measuring the behavior of the full-size vehicles. The characteristics of the various systems and their impact on the dynamics of motion of the vehicle can be determined during stand tests or simulation and confirmed during testing of vehicles on test tracks. Testing vehicles built in small series, oversized or performed individually are conducted infrequently or not at all. In such cases, the alternative may be conducting tests of vehicles carried out at a scale. Research may be conducted in the boundary conditions (which could lead to loss of stability or overturning of the vehicle) impossible to achieve during testing of actual vehicles. They are particularly useful for assessing the stability of vehicles, the impact of the solutions or actions of a driver assistance system. Conducting research vehicles at a scale for the assessment of full-size vehicle must meet the criteria of similarity in the study of physical models of vehicles. One of the major issues is interaction of wheels and road. This article describes the results of wheels interaction with the road for tires with different characteristics used in the mobile model of the car and on the actual vehicle. The aim of the study was to prepare reference material to determine the correlation between the characteristics of the tire model and the full-scale tires. This will allow for made adjustment resulting from the impact of the characteristics of the tires on the motion dynamics of comparable cars especially in the curvilinear motion.

Schlüsselwörter

  • stability of vehicle motion
  • testing vehicles in scale
  • tires characteristics
Uneingeschränkter Zugang

Numerical Research of Toothed Gears Geometry Influence on Power Transmission System Vibroactivity

Online veröffentlicht: 08 Nov 2019
Seitenbereich: 239 - 246

Zusammenfassung

Abstract

The article presents results of numerical studies on the influence of selected factors on the dynamic effects and vibroactivity in power transmission system with toothed gear. Optimization of the constructions of the toothed gears is in many cases only possible by applying the numerical methods. Dynamic models allow determining the influence of a range of factors on the dynamic phenomena occurring during work of toothed gear. The studies were performed with use a custom developed dynamic model of a test stand with the gears operating in the circulating power system. It was assumed, that properly defined and identified model can be used to analyse dynamic phenomena occurring in meshing and bearings of toothed gears and allows optimizing their construction, especially allows minimization their vibroactivity. Numerical calculations were based on two sets of input data. Sets of input data consist information on all parameters included in the model, and which were determined during the identification process carried out in laboratory at two test stands. Selected results of simulations presented in this article prove, that identified dynamic model can be used to analysis of the impact of various constructional, technological and operational factors on the vibroactivity of the toothed gear.

Schlüsselwörter

  • power transmission system
  • toothed gear
  • dynamic model
Uneingeschränkter Zugang

Influence of Toothed Gear Geometry Parameters on Power Transmission System Vibroactivity

Online veröffentlicht: 08 Nov 2019
Seitenbereich: 247 - 254

Zusammenfassung

Abstract

The article presents selected results of experimental studies on the influence of chosen factors on the dynamic effects and vibroactivity of toothed gears in power transmission systems. The studies were performed on test stand with the gears operating in the circulating power system. On initial phase of the research, four pairs of helical gear wheels with the same value of gear ratios were designed and manufactured. The wheels differed by values of transverse contact ratio εα, face contact ratio εβ and total contact ration εC. In the research, the transverse vibration velocities of the shafts and housing of the tested toothed gear on FZG test stand was assumed to be the vibroactivity criterion. The measurements of the vibrations were carried out on the shafts and at seven points of the top plate of the housing. The vibrations were measured using a laser vibrometer and acceleration sensors. In addition, selected experimental results of measurements were compared with results of numerical simulations. To the simulations was used extended, identified dynamic model of the FZG test stand. The parameters of the wheels and the measured deviations were introduced into model. Obtained results confirm that by increasing the value of the contact ratio of the helical gear is possible reduction of dynamic phenomena occurring in the toothed gear.

Schlüsselwörter

  • power transmission system
  • vibroactivity
  • toothed gear
Uneingeschränkter Zugang

Use of Regression Analysis for Comparative Evaluation of Accident Hazard in Poland, by Regions

Online veröffentlicht: 08 Nov 2019
Seitenbereich: 255 - 264

Zusammenfassung

Abstract

Calculations carried out made it possible to characterize changes in the accident hazard, in numerical terms, based on the course of the regression line. An analysis of the distribution, by regions, of the accident hazard and, above all, the showing of changes in this hazard is an important contribution to the actions taken to improve the road transport system. The rate of decrease in the number of accidents undergoes changes, which are particularly conspicuous in some voivodships (provinces) against the background of the general process of decline in the nationwide number of accidents. A graph to characterize this hazard has been presented, plotted with taking into account the changes in the number of accidents, recorded in monthly steps for a period of 7 years. The rate of these changes was also evaluated, in medium-term and short-term intervals. The calculation results were used to ascertain whether a decline in the total number of accidents in Poland is accompanied by similar changes taking place in individual regions. The symptoms of increasing share of the number of accidents that occur in a few regions in the total number of accidents taking place in Poland may be a cause for alarm.

Schlüsselwörter

  • regression analysis
  • road accidents
  • accident hazard by regions
Uneingeschränkter Zugang

Airfoil Selection for Wing in Ground Effect Craft

Online veröffentlicht: 08 Nov 2019
Seitenbereich: 265 - 269

Zusammenfassung

Abstract

The main purpose of this article was to select airfoil, which generates the biggest lift coefficient, with possibly smallest drag coefficient when the airfoil flies in the wing in ground effect. Wing in ground effect occurs in the direct proximity of ground, the article presents wing in ground effect creation mechanism description with automotive and aerospace examples.

The article shows also wing in ground conditions of Ansys Fluent software simulation for all cases with conditions of analysis convergence. The article contains results of the numerical analysis for ten airfoils in three different positive angles of attack in the wing in ground flight; ten airfoils for free stream flight in the same angles of attack as in wing in ground effect, results contains lift and drag coefficients with NACA M8 airfoil presentation as authors choice for wing in ground effect crafts airfoil with full simulation results for angles of attack from –5° to 15°, with profile characteristics.

The article shows physics of stall in the wing in ground effect, and a description why stall in WIG effect flight occurs only with drag coefficient rise without lift coefficient drop, and safety measures for aircraft landing with wing in ground effect influence.

Schlüsselwörter

  • transport
  • ekranoplan
  • numerical analysis
  • wing in ground effect
  • airfoil
Uneingeschränkter Zugang

Evaluation of Transmission Secure Methods in its Systems

Online veröffentlicht: 08 Nov 2019
Seitenbereich: 271 - 278

Zusammenfassung

Abstract

The essence of the operation of all ITS systems is to make decisions based on the information obtained and available. Under these assumptions, these systems are expected to utilize telecommunication, IT, automation and measurement technologies, which, in conjunction with advanced control methods, improve communication. Each ITS subsystem has specific requirements for communications channels that have to be tailored to the needs of the subsystem, its topology, and users, taking into account the costs of both the construction and operation of the system. The article presents issues related to information security analysis in ITS systems. Some selected aspects of risk prevention, which may be an important factor affecting the safety of the transport system, will be analysed. The analysis and evaluation of secure data transmission methods will also be conducted. This analysis and evaluation will select secure transmission methods using VPN virtual tunnelling technologies.

In the article, the selected problems related to the security and confidentiality of information transmission between ITS elements and the provision of protecting access to the IT systems’ resources and their stored data, the aspects of problem affecting the communication system architecture is signalled. The methods for secure transmission in ITSs are secure transmission methods commonly used in systems, which require the confidentiality and security of information transmission between the data source and its recipient.

Schlüsselwörter

  • transport
  • ITS systems
  • security
  • information
  • threats
  • technologies
Uneingeschränkter Zugang

Modelling and Numerical Analysis of Explosion Underneath the Vehicle

Online veröffentlicht: 08 Nov 2019
Seitenbereich: 279 - 286

Zusammenfassung

Abstract

The article presents a method for numerical modelling of interaction of a shock wave on a simplified model of a light armoured vehicle. Detonation of the explosive material occurs centrally underneath the vehicle. The mass of an explosive charge was from 0.5 to 10 kg off TNT. Acceleration, displacement and kinetic energy of the floor plate/panel were verified during the tests.

The model and numerical calculations were carried out using the following programs: CATIA, HyperMesh, LS-PrePost, LS-Dyna. CONWEP approach was applied to describe interaction of a pressure wave on the structure. For each case, the explosive charge was located at the same place under 700 mm from the top surface of the range stand. The results of the calculations present the effects of detonation under the vehicle without a protective system and with the protective system. The proposed protection system is made of low-density materials such as aluminum foam and cork. Thanks to such an approach, the effectiveness of the protective system will be checked to reduce the adverse physical quantities that threaten the health of the soldiers. Thanks to very simple solutions, it is possible to increase passive safety of passers and use of low-density materials will slightly increase the vehicle’s mass leaving manoeuvrability at a similar level.

Schlüsselwörter

  • shock wave
  • LightArmoredVehicle (LAV)
  • CONWEP
  • protective structure
  • IED
Uneingeschränkter Zugang

Design and Optimisation of Main Rotor for Ultralight Helicopter

Online veröffentlicht: 08 Nov 2019
Seitenbereich: 287 - 295

Zusammenfassung

Abstract

A modern main rotor, dedicated to the ultralight helicopter, has been designed and optimised. Due to assumed simplicity of the rotor design and taking into account some technological constraints, the principal purpose of the presented research was to design a dedicated airfoil which, when applied on the main-rotor blades, would influence satisfactory improvement in a performance of the ultralight helicopter, especially in fast flight. The design and optimisation process has been supported by a computational methodology. The in-house software has been used for direct and inverse design of shapes of the rotor-blade airfoils. Aerodynamic properties of the airfoils as well as the helicopter main rotor were evaluated based on both the two-dimensional and three-dimensional flow simulations conducted using the ANSYS FLUENT software that was used to solve U/RANS equations. Based on the results of conducted computational simulations of fast flight of the ultralight helicopter, it can be concluded that the newly designed main rotor, compared to the baseline, may give certain improvement in helicopter performance in fast flight. In addition, the application of this newly designed rotor may lead to increase of a maximum speed of the helicopter flight, due to the greater lift force achievable by this rotor on the retreating blade, which is favourable from point of view of keeping of a lateral balance of the helicopter in fast flight.

Schlüsselwörter

  • rotorcraft
  • ultralight helicopter
  • main rotor
  • airfoil
  • computer-aided design and optimisation
Uneingeschränkter Zugang

Burnishing Treatment of the Faying Surface of the Pipe Flange

Online veröffentlicht: 08 Nov 2019
Seitenbereich: 297 - 303

Zusammenfassung

Abstract

On ships for connecting pipes in seawater installations, fire and other installations and for joining pipes to fittings or receivers, flange-type couplings are often used. It is important to ensure tightness between pipe flanges (ASME). If the system pressure does not exceed 1.6 MPa, “open” flange packing using flat gasket rings is used. Rubber, textolite, polyvinyl chloride or metals and alloys with good plastic properties (e.g. aluminum, copper, Monel alloy, Armco iron) can be used as a sealant material (depending on pressure in installation). The tightness of the joint determines the quality (geometric structure) of the surface of the flange at the contact point with the gasket. Reduced roughness ensures even distribution of surface mounting pressures on flange joint gasket. This article deals with the assessment of the use of burnishing as a finishing treatment for flange faces and the selection of rolling parameters. Samples used for the tests were made of S235J2 carbon steel. Burnishing treatment was done with the SKUV20 tool. The working element of the tool was in the shape of a roller. Burning was performed using the following parameters: the burnishing force (Fn) – 600 N, 800 N and 1000 N; Feed rate (f): 0.08 mm/rev, 0.13 mm/rev, 0.24 mm/rev; the speed of burnishing (vn) – for a diameter of 55 mm – was 45 m/min, 65 m/min, 78 m/min. The research was carried out on the basis of trivalent plan Hartley. As the output variables (dependent variables), the roughness reduction index (KRa) and the (Su) were adopted. Based on the multiple regression analysis, it was found that the greatest impact on reducing roughness and surface hardening of burnished material has burnishing force. The dependence between dependent variables and Fn is proportional. The effect of the burnishing speed (vn) on the values of KRA and Su parameters is statistically insignificant. Machining of the active surface of the pipe flanges should be carried out with a burnishing force of 1 kN, a feed rate of 0.08 mm/rev and a burnishing speed of 45 m/min.

Schlüsselwörter

  • burnishing
  • pipe flange
  • flange face
  • roughness
  • multiple regression
Uneingeschränkter Zugang

The Analysis of the Properties of Ablative Composites with Carbon and MMT Nanofiller Reinforcement

Online veröffentlicht: 08 Nov 2019
Seitenbereich: 305 - 312

Zusammenfassung

Abstract

One of the most important parameters in the selection of composite materials used for the protection of avionics instruments exposed to high temperatures are ablative properties. They constitute the main criterion in determining the composition and thickness of the protective material. In this article, the authors determine the ablative properties of a polymer matrix with carbon reinforcement and check the effect of using the MMT additive (montmorillonite) on the change in the resistance to the impact of a high heat flux. The tested materials play an important role in the defence, aviation and space industry. Ablative materials are the only ones to protect the rear wall surface from an excessive temperature rise while using a thin insulation wall. For the sake of the research, we prepared a series of samples of the composite produced with epoxy resin LH 145, H 147 hardener, carbon fibre mats and the addition of MMT. The prepared samples were tested on a unique stand in laboratory conditions. The findings obtained from the experimental testing after a detailed analysis were tabulated and presented in the form of graphs. The authors determined the ablative loss of mass of the individual samples, compared their internal temperatures, which had been measured with thermocouples, as well as the temperature on the backside of the sample. In addition, in order to complement the experimental studies of determining the temperature rise on the rear surface, the authors used a thermal imaging camera. Besides, they took photos of different layers of the examined structure, which had been exposed, to a heat stream, by means of a scanning microscope.

Schlüsselwörter

  • composite
  • ablative properties
  • nanotubes
  • carbon fibre
  • ablation
Uneingeschränkter Zugang

Analysis Concerning Changes of Structure Damping in Welded Joints Diagnostics

Online veröffentlicht: 08 Nov 2019
Seitenbereich: 313 - 320

Zusammenfassung

Abstract

Among non-destructive testing methods of welded joints, a vibrodiagnostic method is one of the most promising in applications intended for the continuous monitoring of the structure. The accelerometer-recorded responses provide diagnostic information that requires mathematical processing to extract the essential features typical of the tested welded joints and to evaluate their execution. For this purpose, the proposed method was based on the determination of damping decrement in function of time. Due to the complexity of the responses run, a proposed method consisted of calculating the damping decrement using the response approximation with different functions. It has been shown that the changes analysis of damping decrement applied to welded plates enables the assessment of the quality associated with the weld. Attention was also paid to the elements relevant to the study. This work presents the algorithm and exemplary results obtained from the application of proposed method to several selected sample plates with different type of welds. A scientific apparatus, which purpose was to record dynamic characteristics of welded joints was also described.

Schlüsselwörter

  • diagnostics
  • welded joints
  • non-destructive testing
  • NDT
  • SHM
  • vibration
  • spectrum analysis
  • damping decrement
Uneingeschränkter Zugang

The Conception of Modular Monitor of Car Exploitation Parameters

Online veröffentlicht: 08 Nov 2019
Seitenbereich: 321 - 326

Zusammenfassung

Abstract

Current tendencies in electronics and informatics development going towards Internet of Things (IoT), Big Data or Data Cloud technologies create new possibilities in acquiring and utilizing data. The article presents the concept of modular monitoring of vehicles operating parameters. Presented device registers data from the OBD system and a set of independent, configurable sensor modules. Data from the OBD system is acquired via protocol. CAN Bus with a DLC connector. The signal from sensor modules is transferred via a Bluetooth wireless network. The registered data can be storage on board as CD card memory or alternatively on a typical user interface such as laptop, tablet, cell phone etc. The communication with the user interface is realised with USB. Moving vehicles modular monitoring system presented in the article can be used to attain a fuller representation of the vehicles state in relation to its environment. The base assumption of the device is maximal flexibility in term of sensors versality as well as possibilities of assembly on board. In connection with the concept, a prototype of the device was made and tested with an inertial measurement unit (IMU) module and a pressure sensor. Appliances modules are based on Cortex M4 and M0 processing units. A users interface in LabVIEW and examples of registered signals are showed at the end of the article.

Schlüsselwörter

  • automotive
  • communication networks
  • car parameter monitoring
  • CAN
  • modular system
Uneingeschränkter Zugang

Use of 3D Printing Technology in the Aviation Industry on an Example of Numerical Experimental Stress State Analysis of Unmanned Aerial Vehicle Wing

Online veröffentlicht: 08 Nov 2019
Seitenbereich: 327 - 334

Zusammenfassung

Abstract

The article presents the results of static tests performed on the primary support structures of a TWISST-ter unmanned aircraft constructed using additive manufacturing techniques commonly known as 3D printing. The primary goal of the experiment was determining the material effort of the structure in order to assess the feasibility of such an engineering solution in terms of material mechanics. Considering the fact that the properties of 3D printed elements are not widely known, both destructive experimental methods and finite element methods were used. During the experimental trails, the ARAMIS deformation measurement system, based on digital three-dimensional image correlation, was used. The results of this experiment allowed for the calibration of the numerical model as achieving convergence with experimentally determined strain fields. This approach ensured the correctness of the numerical determined stress state. Based on the results of the study, the necessary design improvements were implemented and a general conclusion was formed regarding of the numerical analysis of structures made through 3D printing.

Schlüsselwörter

  • DIC
  • 3d printing
  • FFF
  • stress state
  • UAV
Uneingeschränkter Zugang

Geometrical Structure for Endoprosthesis Surface Lubrication and Wear Prognosis

Online veröffentlicht: 08 Nov 2019
Seitenbereich: 335 - 341

Zusammenfassung

Abstract

It can be stated that over the last ten years in the European Union, the number of bone fractures caused by osteoarthritis has increased twofold. More than 100,000 hip or knee joints in total were implanted in Germany during one year. Within ten years, 5% of them have failed by aseptic loosening. The non-invasive determination of friction forces and control of their values during lubrication of cartilage cells on the superficial layer of human joint surfaces before implantation has a significant but not sufficient impact on the observation of the early abrasive wear of the cartilage joint and development of osteoporosis. From this fact was drawn the inspiration for the performed investigations related to the endoprosthesis surface parameters because knowledge of the roughness of prosthesis surfaces and friction forces and their control methods permits provision of a necessary standard deviation of the gap height and finally information about the implantation possibility. This article has been prepared based on the objective of European Project UE Grant IRSES,612593, 2013-2016 to represent the methodology and goal of the idea described in and make a wider discussion possible on this subject for further developments during the realization. To the research methods and materials used in this article realization belong: Rank Taylor Hobson-Talyscan 150 Apparatus implemented by Talymap Expert and Microsoft Excel Computer Program connected with the Mathcad 15 Professional Program and a new semi-analytical methods of probabilistic and statistic prognosis applied for theory of hydrodynamic lubrication of the curvilinear orthogonal surface and coordinates extended to the friction and wear problems of the endoprosthesis surfaces during the exploitation.

Schlüsselwörter

  • endoprosthesis
  • surface
  • measurements
  • gap height
  • wear
  • random prognosis
Uneingeschränkter Zugang

Research on Composite Materials in the Institute of Aviation

Online veröffentlicht: 08 Nov 2019
Seitenbereich: 343 - 348

Zusammenfassung

Abstract

This article contains information on new duties of Centre for Composite Technologies (CCT) managers, implemented to increase their efficiency. Methods of quality improvement of aeronautical composite materials testing are presented. It was achieved by correct test plans definition, performing mechanical and physicochemical tests up to allowable composite generation. Several tests of this type are listed which are executed according to international standards of American Society for Testing and Materials (ASTM), including those in extreme temperatures. Effect of Lean Sigma and DMAIC (Define, Measure, Analyse, Improve, Control) implementation in the lab of CCT is shown. Results of bearing strength of quasi-isotropic laminate (carbon fibre and epoxy resin) with a bolt in different ambient conditions are presented. Moreover, the article discusses methodology of tension and shearing strength determination in the case of composite specimens diverging from others with application of statistical MNR method (Maximum Normed Residual). MNR coefficients are then compared with Critical Values.

Schlüsselwörter

  • composites testing
  • carbon-epoxy pre-impregnates
  • Maximum Normed Residual
Uneingeschränkter Zugang

Gyroplane Rotors Vibration Tests

Online veröffentlicht: 08 Nov 2019
Seitenbereich: 349 - 354

Zusammenfassung

Abstract

The article presents vibration test of three different types of gyroplane main rotors. The test was carried out on a specially prepared test bench using a Red Led Tacho Sensor measuring system. Tests were conducted for the project „Research and development works on innovative construction of aircrafts of weight over 560 kilograms at the company Trendak Aviation”. The work outlines the basic properties of the gyroplane vibration and gives their sources. The research focused on the gyroplane main rotor vibration related inter alia to the rotor imbalance as well as rotor hub connector construction. Tested rotors consisted of three different types of gyroplane rotor blades and innovative universal hub connector with positive coning angle of 2.8º. The article summarized the basic properties of three types of gyroplane the rotor blade, marks advantages of use hub connector witch constructional dihedral angle. Discusses the principle of operation of measuring device, tests methodology starting from instrument calibration. The results of the measurements are shown in the graphs in polar coordinates. The vibration measurement is carried out in two axes, in x-axis, longitudinal, along the rotor radius and in y-axis, perpendicular to the x-axis, in the direction of the chord of the rotor blades.

Schlüsselwörter

  • rotor vibration
  • rotor blades
  • teetering rotor
  • hub connector
  • rotor imbalance
Uneingeschränkter Zugang

Evaluation of Operational Availability of Municipal Transport System

Online veröffentlicht: 08 Nov 2019
Seitenbereich: 355 - 361

Zusammenfassung

Abstract

The primary subject of research is the procedure leading to safe, efficient, reliable and timely completion of transport tasks. The tasks, assigned to the transport system, are carried out by an operative subsystem, comprised of elementary subsystems of the man – technical object (operator-vehicle) type. The timely and safe completion of the tasks is influenced by the level of availability and reliability of elementary subsystems. Those in control of the process of the use of means of transport (vehicles) should undertake control decisions in such a way that would correctly evaluate the efficiency of process completion. In the area of public transport, technical availability of buses constitutes an important criterion of the evaluation of transport system. As a result, the transport company should provide continuous surveillance of the process of vehicle use in order to achieve running availability of the whole system. The requirements expected from devices and machines used head towards servicing via preventive method taking into account the technical condition of the system. Such an approach is a transformation towards technical system servicing process management. Correct completion of transport tasks is possible when the required traffic safety is met, taking into consideration the technical condition of the means of transport. The municipal transport systems should ensure the quality of the services provided to meet the expectations of the users. In the set of characteristics of the researched transport system, the following ones stand out: regularity, availability, reliability, course frequency, travel comfort, timeliness, speed, service complexity, competitive cost of transport service, and safety.

Schlüsselwörter

  • transport
  • road transport
  • simulation
  • combustion engines
  • air pollution
  • environmental protection
Uneingeschränkter Zugang

Aerodynamic Effect of Turbo Prop Engine Slipstream on Aircraft Tail Assembly Vibration

Online veröffentlicht: 08 Nov 2019
Seitenbereich: 363 - 367

Zusammenfassung

Abstract

The article presents a computational analysis of the effect of the turboprop engine slipstream on generation of aerodynamic forces induced vibrations of aircraft tail assembly (empennage). Working propellers exhaust system, engine nacelle, and wing-engine nacelle flow interference phenomenon can cause strong non-stationary disturbances behind the wing of the aircraft. These disturbances, propagating in the direction of the aircraft tail assembly, may be an important factor influencing the operation of the airplane flow control system and the source of aerodynamic forces generating vibrations of the entire plane structure. The article presents an example of analysis of this phenomenon for a light passenger-transport aircraft using advanced numerical models for simulation of the flow around the aircraft. In the computational model, Navier-Stokes flow equations were solved by finite volume method with the K-Omega SST turbulence model to calculate the turbulent kinetic energy distribution in the flow slipstream behind the airplane propulsion unit. The Ansys Fluent commercial solver was used to run analyses. To perform the simulation, high quality, dedicated conformal computational mesh, consisting of hexahedral and tetrahedral elements was prepared to evaluate the propagation of the flow disturbances with limited numerical dispersion effect. Mesh generation was conducted using Ansys ICEM CFD and Mesher software. Unsteady aerodynamic forces for horizontal and vertical tail-planes of the airplane were computed during simulations. Fourier analysis of the driven forces was performed, which resulted in finding the dominating vibration frequencies generated by the flow field around the tail assembly. The visualization of the flow field and the regions of the strong disturbances were presented. Results can be exploited in the pre-design process of aerodynamic configuration of multi-engine aircrafts.

Schlüsselwörter

  • air transport
  • aerodynamic wake
  • nacelle
  • tail assembly
  • vibration
Uneingeschränkter Zugang

Optimizing the Number of Docks at Transhipment Terminals Using Genetic Algorithm

Online veröffentlicht: 08 Nov 2019
Seitenbereich: 369 - 376

Zusammenfassung

Abstract

This article presents the issue of designating the number of docks at the transhipment terminals using genetic algorithm. Transhipment terminals refer to cross-docking terminals. The main factor that influences on the number of these docks is the stream of cargo flowing into the given terminal. In order to determine this flow of cargo the mathematical model of the distribution of this flow was developed. This model takes into account constraints like those that e.g. processing capacity at the transhipment terminal cannot be exceeded or demand of recipients must be met. The criterion function in this model determines the minimum cost of the flow of cargo between all objects in the transport network. To designate the optimal stream of cargo flowing into the transport network the genetic algorithm was developed. In this article, the stages of construction of this algorithm were presented. The structure processed by the algorithm, the process of crossover and mutation were described. In the article in order to solve the problem of designating the number of docks at the transhipment terminals the genetic algorithm was developed.

Schlüsselwörter

  • transhipment terminals
  • genetic algorithm
  • optimization
  • cross docking
Uneingeschränkter Zugang

A Method of Assessing the Tendency of Aviation Fuels to Generate Thermal Degradation Products Under the Influence of High Temperatures

Online veröffentlicht: 08 Nov 2019
Seitenbereich: 377 - 384

Zusammenfassung

Abstract

The subject of the article concerns the issues associated with thermal degradation of aviation fuels under high temperature conditions. Due to the intensive development towards increasingly higher thermal loads for both, turbine aviation engines, as well as the used fuels, the issue of thermal stability of the fuel itself is extremely important. In aviation, the fuel, apart from direct participation in energy generation during the combustion process of a fuel-air mixture, also takes part in the heat transfer in many aircraft systems. As a result, requirements in terms of the fuel’s thermal potential are increasingly higher. The standard method for determining the thermal stability of fuel executed on a JFTOT device proves to be insufficient in the context of the appearing issues in current operation. The article presents a non-standard approach to the assessment of aviation fuel thermal degradation with the use of a specialist test rig. The authors believe that the presented methodology and the measurement capabilities of the test rig are valuable supplementary material for the standardized thermal stability test. It allows more thoroughly understanding the phenomena undergoing in the fuel impacted by high temperatures. The article has been prepared within the research project no. 2011/01/D/ST8/06567 funded by the National Science Centre in Poland.

Schlüsselwörter

  • jet fuel
  • turbine engine
  • thermal stability
  • test rig
  • non-standard method
Uneingeschränkter Zugang

Application of Similarity Method of Distance Courses Describing the Elements Content in Concrete Intended for Airfield Pavements

Online veröffentlicht: 08 Nov 2019
Seitenbereich: 385 - 392

Zusammenfassung

Abstract

The work presents the applied similarity methods of distance courses in case of cement concrete intended for airfield pavements. Composition of concrete mixes was designed and their parameters were defined. Compressive strength of hardened concrete and components thereof and the occurrence of crystal phases were determined. Subject to observations of internal structure of concretes and conducted chemical microanalyses using scanning electron microscope, the contents of diversified elements in four zones were specified. Similarity indexes between input and target sequence were defined. Diagrams presenting the similarity of the analysed concretes were prepared. It was proved that the suggested method could be used to assess the elements content and define the similarity of concrete intended for airfield pavements. The scope of works consisted of two stages. During the first one, two series of cement concrete were prepared. The analysis included cement concretes intended for airfield pavements, in compliance with requirements. The influence of variable environmental conditions with respect to standard ones on the selected features of hardened concretes was assessed.

Schlüsselwörter

  • cement concrete
  • airfield pavement
  • analysis of similarity
Uneingeschränkter Zugang

Application of Similarity Method of Distance Courses Describing the Elements Content in Pavement Quality Concrete

Online veröffentlicht: 08 Nov 2019
Seitenbereich: 393 - 398

Zusammenfassung

Abstract

The publication presents the application of similarity analysis of distance courses. This method has been applied to define similarity of cement concrete intended for airfield pavements. The scope of works included standard concretes intended for airfield pavements and concretes after frost resistance test. The test has been conducted in diversified media used in the course of winter maintenance. The nature of resistance of pavement quality concrete was discussed with respect to frost resistance thereof. Research procedure was presented and the obtained laboratory tests results were discussed. Concrete samples were subject to observations using scanning electron microscope in order to define changes occurring in the internal microstructure. Chemical microanalysis of concrete composition before, in the course of and after the frost resistance test and the occurring changes were specified. The obtained laboratory tests results were intended for the purposes of the similarity analysis. Results obtained in case of standard pavement quality concrete were considered as comparative values. Characteristics of the remaining concretes were referred to these values and then similarity of distance courses were analysed. It was proved that BWMt concrete was the most similar concrete to the comparative concrete.

Schlüsselwörter

  • cement concrete
  • airfield pavement
  • analysis of similarity
49 Artikel
Uneingeschränkter Zugang

The Power Impact of Electric Power Assist in Hybrid Vehicle

Online veröffentlicht: 08 Nov 2019
Seitenbereich: 1 - 1

Zusammenfassung

Abstract

The current interest in the development of hybrid vehicles is a response to serious effects of road transport on the environment over recent years. In addition, vehicles equipped with this type of drive combine the advantages of a conventional diesel engine and electric motor. This results in higher system efficiency while reducing emissivity.

This work seeks to demonstrate the effect of electric power on the total power of a hybrid vehicle. The research on the chassis dynamometer (MAHA LPS 3000) of the hybrid sports car, Honda CRZ, has been performed in three modes of operation: normal, economical and sport. The obtained results are presented in the form of graphs of external engine characteristics, where the influence of electric power on the system is visible.

The tested vehicle is equipped with sixth version of Honda’s Integrated Motor Assist (IMA) technology, which is the crucial system, assisting the combustion engine in order to provide higher performance and better fuel economy.

Schlüsselwörter

  • hybrid vehicle
  • Honda CR-Z
  • electric motor
Uneingeschränkter Zugang

Electromagnetic Launcher Aviation Gun of the Future

Online veröffentlicht: 08 Nov 2019
Seitenbereich: 7 - 16

Zusammenfassung

Abstract

The electromagnetic rail launcher is a type of high-energy weapon that uses a strong magnetic field to project missiles. To create this field, a current pulse source is needed to provide sufficiently high voltages and currents. The study thoroughly examines the principle of electromagnetic operation of the rail launcher, with particular emphasis on how to achieve the highest electromagnetic field strength. The analysis has been subjected to the source of the impulse current and the tendency of their development in the near future. The subject of the appropriate rails selection and their mutual arrangement has been touched up to attain adequate strength against the harmful effects associated with the flow of high currents. Considerations have been taken to protect the rails from the harmful effects of large-scale current flows, and the topic of the projectile itself to the electromagnetic field was raised. The rapid development of technology over the last few years indicates that high-energy weapons will be the basic weapon of all types of forces in the near future. The development of electromagnetic railroads requires the solution of many mechanical problems and harmful phenomena.

Schlüsselwörter

  • electromagnetic rail launcher
  • electromagnetic railgun
  • electromagnetic field
  • magnetic field
  • pulse source
  • missiles
  • rails system
  • compulsator
  • magnetic materials
Uneingeschränkter Zugang

Energy State Impact on Friction and Wearing in Combustion Engines

Online veröffentlicht: 08 Nov 2019
Seitenbereich: 25 - 30

Zusammenfassung

Abstract

Friction pairs are designed from elements, where is very difficult to define in unequivocal way all optimal parameters. Research on stability of friction pairs are focused on the surface and the top layer of surface in the parts. The main goal is find new solutions to design and material, thereby achieving one million kilometres of mileage to main repair in the case of internal combustion engines. The biggest structural difficulties are noticeable in friction pairs where we can observe sliding and returning motion, which is also connected with sealing function. Piston – ring – cylinder assembly of combustion engine has many friction pair’s examples, also one of them, which decide about fastness to wear. A typical example of such a pair is first sealing ring – cylinder sleeve, called further in piston – rings – cylinder unit in combustion engine. Engineers are currently seeking an additional factor, which would be unable to gain the reduction of tangential force by reducing the friction coefficient in elements of friction pair during operations. Such a factor may be the surface free energy that results from molecular structure and nature of the bonds between the molecules present in the material. Components of surface free energy determine the tribological properties of the material, which is reflected in the stability of the units. The work aims to show the possibilities and benefits of the application of this new method in order to reduce wearing, which is consistent with the observed trend of technology development.

Schlüsselwörter

  • friction
  • energy state
  • combustion engines
  • wetting drop
  • tribology
Uneingeschränkter Zugang

Dynamic Weighing System Used in Excavator

Online veröffentlicht: 08 Nov 2019
Seitenbereich: 31 - 38

Zusammenfassung

Abstract

In many industrial applications is taken to consider change of payload potential energy while lifting it. It allows obtained directly benefits. For example, the cost of material loaded on a dump truck in a composition of coal is generally priced by its weight. In this case, the truck has to pass a stationary scale twice to identify its payload, before and after loading. Measuring weight of the material instantly while loading the truck, increases the efficiency of the process and makes a stationary scale unnecessary. In addition, it is possible to prevent overloading of means of transport, which use public roads, and can be weighed by the road service. The typical solutions of the static and dynamic weighing system from market were compared. The theoretical model is presented basing on geometrical and mass parameters of excavator CAT 301.5. The weighing system used in off-road machines is usually based on the measurement of the working fluid pressure in the piston chambers of the hydraulic cylinders, which lift the machine work equipment together with a payload. In this article is shown a solution with load pin, which allows the determination of the load mass independently of the several factors affecting the classic weighing system. The possibility of payload mass measuring on the excavator was estimated during tests on prepared research stand. There were obtained a good agreement of experimental research results with the mathematical model.

Schlüsselwörter

  • weighing
  • excavator
  • load pin
  • pressure
  • pay load
Uneingeschränkter Zugang

Comparative Analysis of the Operating Indexes of Manually and Automatically Controlled Passenger Car Powertrain System at Variable Load States

Online veröffentlicht: 08 Nov 2019
Seitenbereich: 39 - 46

Zusammenfassung

Abstract

This article reports the results of a study into operating parameters of a system consisting of an SI engine and a powertrain in a Fiat Panda passenger car in the conditions of a variable load. The analysis was primarily concerned with the variability of fuel consumption resulting of the changing load applied to the driving wheels in the conditions of a test performed on chassis dynamometer for manual and automatic controlled transmission gear change The test bench included a dedicated driving cycle, which was developed as cycle with periodically changed constant linear speed of the car every 10 km/h. According to the vehicle set speed, the load on its wheels was determined by the basic resistance as rolling resistance, air resistance and resistance corresponding to road inclination. Each period of a drive cycle corresponding to steady state driving gave the average instantaneous values of drive system performance indicators. The waveforms of these indicators were recorded and then averaged and presented as representative points of the powertrain system that were analysed. The focus of the study involved the identification of the points characterized with the minimum specific fuel consumption and impact of type of powertrain control on emission of CO2 from passenger car SI engines.

Schlüsselwörter

  • fuel consumption
  • spark ignition engine
  • variable load
  • engine efficiency
  • motion resistance
Uneingeschränkter Zugang

Semi-Markov Model of Multi-Modal Transport Operation

Online veröffentlicht: 08 Nov 2019
Seitenbereich: 47 - 54

Zusammenfassung

Abstract

Multi-modal transport means the transport of the objects through at least two different carriers of any combination of simple tasks of transport carriers (by truck, by train, by ship or by plane). A Semi-Markov (SM) model of multi-modal transport operation is presented in the article. The SM process is defined by the renewal kernel of that one. In our model, time to failure of the operation is represented by a random variable that denotes the first passage time from the given state to the subset of states. The duration of one operation cycle is a random variable representing the return time to the initial state. The appropriate theorems of the Semi-Markov processes theory allow us to calculate characteristics and parameters of the transport operation model.

The article presents the example of the transport operation final part of container with cargo from Warsaw to Stockholm, where from Warsaw to Gdynia, the container is transported by lorry, from Gdynia to Karlscorona by ferry and from Karlscorona to Stockholm by truck.

Schlüsselwörter

  • Semi-Markov model
  • multistage transport operation
  • reliability function
  • mean time to failure
Uneingeschränkter Zugang

The Assessment of Surface Layers Texture of the Fouling Gathered on the Heat Transfer Surfaces within Regenerative Feedwater Heat Exchangers

Online veröffentlicht: 08 Nov 2019
Seitenbereich: 55 - 60

Zusammenfassung

Abstract

The fouling presence on the heat transfer surfaces, both on the waterside and the steam side of the steam power plants heat recovery exchangers usually leads to the loss of their heat transfer capacities. This loss appears owing to the high value of heat resistance of fouling. Furthermore, these deposits are most often formed with irregularities in the surface layers. These textures are usually characterized by a varied, often stochastic and difficult to define, geometric structures. The most common measure of their inequalities is the roughness parameter describing the surface geometry. The fouling surface layer texture can, on one hand, cause enhancement of the heat transfer process, but on the other hand, it may contribute to an additional increase in thermal degradation of the heat exchanger. Many experimental studies have shown that the greater the unevenness of the heat transfer surface on the waterside of a given heat transfer device, the smaller increase in the thermal resistance of the impurities over time, thereby increasing the amount of heat transferred. It should be emphasized, however, that the rise in roughness results in an increase in the heat transfer coefficient, while simultaneously intensifying the flow resistance of the working medium. Taking into account the heat transfer surface by steam side, the increase in the roughness promotes the formation of a thicker condensate layer, thus impairing the condensate drainage organization. It can be explained by the fact that deposits settle in a sort of quasi-rib effect, although with undefined ribbed grid, it may lead to the overflow of inter-finned passages. The article shows the previously mentioned phenomena and also presents the descriptive quantities for the fouling surface layer texture, based on the results of the author’s own experimental research.

Schlüsselwörter

  • steam power plants
  • heat recovery devices
  • fouling
  • surface layer texture
Uneingeschränkter Zugang

Description of the Pneumatic Work Cycle of the Starting Unit of the UAV Launcher

Online veröffentlicht: 08 Nov 2019
Seitenbereich: 61 - 70

Zusammenfassung

Abstract

The publication presents a UAV pneumatic launcher designed and built in ITWL. The basic element of the pneumatic launcher is the launch mechanism. The starting mechanism determines the energy parameters that will be reached on the launch pad. The work of the launch engines used in propulsion systems has been reviewed and their advantages and disadvantages are discussed when used in pneumatic launchers. A detailed description of the author’s solution of the pneumatic launching mechanism from the launcher is presented. In order to determine guidelines for the design of pneumatic starter systems, a description of the cycle of operation of the complex pneumatic system was analysed. The description of the pneumatic system’s work cycle was based on the parameters of the flow of the compressed air C and b (C – the sound conductivity of the pneumatic element, b – the critical pressure of the pneumatic element). A set of equations describing the pressure change in the filled and emptied valve compartment and the equation of motion are presented. The equations of a mathematical model describing the pneumatic component and the replacement value of flow parameters for the pneumatic system of series pneumatic components are presented. For the mathematical model, a calculation algorithm is presented which takes into account the initial conditions and the boundary conditions of the various periods of the pneumatic system cycle. Examples of calculation results for a specific pneumatic trigger mechanism are shown. The results obtained were compared with the results of the pneumatic starter station tests and the mathematical model of the pneumatic starter was evaluated.

Schlüsselwörter

  • launcher
  • pneumatic trigger
  • pneumatic system
Uneingeschränkter Zugang

Project Zeus: Video Based Behavioural Modelling of Non-Linear Transportation System for Improved Planning &Urban Construction Projects

Online veröffentlicht: 08 Nov 2019
Seitenbereich: 71 - 81

Zusammenfassung

Abstract

The ability to analyse the traffic and urban mobility pattern with the help of video analytics, which occur in massive volumes of surveillance video will lead us to provide a knowledge based for the urban planners and policy makers to come up with better construction planning. This will soothe the needs of urban commuters and thereby saving unnecessary spillage of money on the construction projects. In this research project, we present an artificial intelligence framework for transport video analytic; which autonomously models behavioural patterns of commuters and flow of traffic, wherein it taxonomically classifies essential patterns based on geometrical feature points of interest to facilitate reality mining. This behavioural pattern of commuter and traffic flow can later be queried and fetched through the newly mathematically programmed ontological data warehousing module, where such reality mined contextual data could be used for sharing essential data.

Schlüsselwörter

  • Algorithms
  • computer vision
  • traffic activity recognition
  • event detection
  • activity analysis
  • behaviour modelling
Uneingeschränkter Zugang

Method of Preliminary Evaluation of Biocomponents Influence on the Process of Biofuels Combustion in Aviation Turbine Engines

Online veröffentlicht: 08 Nov 2019
Seitenbereich: 83 - 90

Zusammenfassung

Abstract

The aim of this article is presentation of the new method of preliminary evaluation of biocomponents influence on the process of biofuels combustion in aviation turbine engines. This method is based on the tests of evaluated biofuels on engine stand MiniJetRig equipped with small turbine engine. The idea of this new method is to compare the combustion process of evaluated biofuel with the combustion of reference fuels. The reference fuel used in presented research was mineral Jet A1. Two compositions of pure hydrocarbons were blended with Jet A1 fuel and tested using MiniJetRig. The main criterion of combustion process assessment was CO concentration in exhaust gases. As the final criterion of evaluated biofuel the ∆CO = [COWx – COJet] was adopted, where COWx – the concentration of CO in exhaust gases emitted during combustion of evaluated fuel and COJet – the concentration of CO in exhaust gases emitted during combustion of Jet A1 fuel. This method was preliminary verified using HEFA biofuel previously accepted for aviation application. The obtained results qualify this biofuel as similar to Jet A1 ones – the DCO was within limits –30 – +20. The presented method needs further research, using much more evaluated fuels, to confirm their usefulness for laboratory pre-selection of new biofuels.

Schlüsselwörter

  • Fuels for aviation turbine engines
  • biofuels
  • synthetic hydrocarbons
  • engine tests
Uneingeschränkter Zugang

Theoretical and Experimental Investigation of a Ground Resonance Phenomenon for the ILX-27 UAV Helicopter

Online veröffentlicht: 08 Nov 2019
Seitenbereich: 91 - 98

Zusammenfassung

Abstract

Ground resonance is an unbalance of the helicopter main rotor rotation caused by its asymmetry. Whilst the helicopter is in contact with the ground this asymmetry generates a divergent and often destructive oscillations of the helicopter structure. These oscillations are self-excited. This paper present results of both theoretical and experimental investigations of this phenomenon. They were dedicated to the new polish UAV helicopter ILX-27. The theoretical analysis were done with commercial software ANSYS using Finite Element Method. The virtual model of the helicopter model accurately reproduced the geometry of all elements of the helicopter and was easy to modify to simulate various kinds of damages. Calculations were done for the following cases: C1 – the helicopter standing on the ground with zero thrust of the rotor, C2 = C1 + helicopter with additional support of the rotor mast, C3 = C2 + thrust of the rotor equal to the total mass of the helicopter, C4 = C2 + fixing the helicopter to the ground, C5 = C2 + helicopter with additional mass. At the beginning the modal analysis for all cases was done – natural frequencies and modes of the structure were identified. Next, for selected cases, harmonic analysis was performed – the structure of the helicopter was loaded with concentrated harmonic forces. Finally the dynamic analysis gave time courses of blades and the hub center motions in the case of structural damages. All phases of simulations were correlated with ground tests of the helicopter prototype. This allowed to compare results of theoretical investigations. These results also supported tests of the prototype.

Schlüsselwörter

  • ground resonance
  • dynamics of helicopter structure
  • finite element method
  • simulation
  • ground tests
Uneingeschränkter Zugang

Research Performance of Novel Design of Diesel Engine

Online veröffentlicht: 08 Nov 2019
Seitenbereich: 99 - 108

Zusammenfassung

Abstract

Certain results of the comparative studies of the high-speed Diesel engine V-12 of the “W” series were presented in the article. The engine was modernised in regard of possibilities to achieve better performances at specific fuel consumption, smaller exhaust emission, smaller scavenge, lower noise and better thermal stability. The subject of this work is the piston cast of novel composite silumin. The development of novel composite silumin (aluminium-silicon alloy), which contains a little more Copper and Nickel, and the introduction of novel alloyed elements, such as Chromium, Molybdenum, Tungsten, increases the strength of the alloy and its thermal stability during successive heating and cooling. The pistons made of this alloy may have a little bigger outside diameter than the pistons made of PA-12 standard alloy, and a smaller clearance between the piston and cylinder liner. The pistons made of standard and novel alloy were mounted successively in the “W” engine. The full load and part load curves were determined. The lubrication oil consumption, fuel consumption, exhaust emission, blow-by and noise were determined too. The article presents the results of the above-mentioned research. The novel composite alloy enables further engine modernization because the engine should operate at higher pressure and temperature in the combustion chamber.

Schlüsselwörter

  • internal combustion engine
  • Diesel engine
  • engine piston
  • composite alloy
  • thermal stability
Uneingeschränkter Zugang

Properties of Novel Composite Alloys Used for the Engine Pistons

Online veröffentlicht: 08 Nov 2019
Seitenbereich: 109 - 116

Zusammenfassung

Abstract

The article presents the results of the investigations cover novel composite silumins with new alloying additives, such as chromium and molybdenum (not yet used in this type of silumin) and increased content of nickel and copper. The samples strength tests were performed at room temperature (20°C) and at elevated temperatures (up to 350°C), and were carried out using the strength machine, equipped with the special climate chamber. The dimensional stability of the new aluminum alloy was investigated using the precision dilatometer. This device allows one to register and record the sample dimensions as a function of temperature, during sample heating and cooling. During the DTA crystallization process investigations, derivative curves have been determined, that allows the analysis of the solidification process and the analysis of the heat transfer process in the sample structure and phase transformations. In the article shows the derivative curve and representative microstructures, and characteristic temperatures for the conventional AlSi12 alloy and novel composite alloy. All research results indicated that the newly developed composite aluminum alloy has far better parameters than aluminum alloys used previously for pistons of the internal combustion engines.

This article concludes with a summary of the advantages of the new composite alloys.

Schlüsselwörter

  • novel composite alloys
  • the engine pistons
  • thermal derivative analysis
Uneingeschränkter Zugang

Verification of the Precise Position of the Aircraft in Air Navigation Based on the Solution of the RTK-OTF Technique

Online veröffentlicht: 08 Nov 2019
Seitenbereich: 117 - 124

Zusammenfassung

Abstract

The article presents the possibility of applying the differential technique RTK-OTF to recover the position of the aircraft in the post-processing mode. Within the framework of the conducted research, the authors designated the geocentric coordinates XYZ of the aircraft and compared them. In the research experiment, they used archive materials from the test flight of the aircraft Cessna 172 around the airfield in Deblin on 1 June 2010. The actual position of the aircraft Cessna 172 was recovered on the basis of GPS kinematic observations registered by the receiver Topcon HiperPro mounted on board the aircraft. In the calculations, the authors also used static GPS observations from the reference station REF1 as well as virtual reference stations VirA and VirB. The final coordinates of the aircraft Cessna 172 with three independent determinations RTK-OTF were defined in the AOSS v.2.0 programme. On this basis, they made verification of accuracy in determining XYZ coordinates of the aircraft Cessna 172. The dispersion of results for the difference in the designation of the X coordinate of the aircraft ranges from –0.19 m to +0.05 m. On the other hand, the size of the difference in the designation of Y-coordinate of the aircraft ranges from –0.07 m to +0.11 m. In addition, the dispersion of the results for the difference in the designation of the Z coordinate of the aircraft is from 0.19 m to +0.12 m.

Schlüsselwörter

  • GPS
  • RTK-OTF
  • accuracy
  • air navigation
  • RMS
Uneingeschränkter Zugang

Fuzzy-Lyapunov Based Controller for a Quadrocopter

Online veröffentlicht: 08 Nov 2019
Seitenbereich: 125 - 132

Zusammenfassung

Abstract

Quadrocopters are nonlinear and inherently unstable systems. To be able to account for the nonlinearities during more aggressive manoeuvres nonlinear control methods need to be utilized to obtain the desired position while at the same time guaranteeing stability. In the article, the quadrocopter dynamics is modelled using the Newton-Euler method. The propeller aerodynamics is modelled using a combination of momentum theory and blade element theory. There are two different control objectives; the 1st objective requires the quadrocopter to reach a desired attitude set point using, while the 2nd objective requires the quadrocopter to track an attitude trajectory. In both cases, Lyapunov stability criterion, in conjunction with LaSalle’s invariance principle, is used to guarantee the system becomes asymptotically stable. In the case of reaching the desired attitude set point, a direct Lyapunov control method is implemented with the control constants determined empirically. For the trajectory tracking, limited knowledge is assumed on the system dynamics and the Mamdani fuzzy controller is used with a rule base that satisfy the Lyapunov stability criterion. The fuzzy membership functions developed empirically and a centre of gravity defuzzification method is used. All simulations are done in MATLAB/Simulink. The results of the numerical simulation are presented in the article.

Schlüsselwörter

  • quadrocopter
  • fuzzy control
  • Lyapunov stability
Uneingeschränkter Zugang

The Influence of Changing of Cutting Parameters on Temperature and Cutting Forces During Turning Process of Stainless Steel With CCET09T302R-MF Insert

Online veröffentlicht: 08 Nov 2019
Seitenbereich: 133 - 140

Zusammenfassung

Abstract

One of the greatest problems of modern production techniques is the achievement of an appropriate quality at minimal costs and accompanied by the production efficiency increase. Therefore, while designing the production process, the technology used should have a considerable influence on the durability and reliability of machine parts to be produced. During finish treatment, the final dimensions as well as functional properties are imparted to a given element by application of proper treatment type. The engineer has a range of production techniques to choose for the proper surface layer formation. It is crucial to find a suitable solution which will meet the requirements as well as the work conditions of a given machine part. The article presents the results of influence of change of cutting parameters on temperature and cutting forces during turning process of stainless steel. A shaft made of 304L stainless steel was used for the research. The cutting process was carried out on a universal CDS 6250 BX-1000 centre lathes. Measurement of cutting forces during lathing process used DKM 2010 turning dynamometer. The turning process was conducted by a cutting tool with CCET09T302R-MF insert by DIJET. During the turning, the following machining parameters were used: cutting speed Vc = 226 m/min, feed f = 0.044, 0.062, 0.083, 0.106 mm/rev and cutting depth ap = 0.25, 0.5, 0.75, 1.0 mm. The chemical composition of steel was measured by Solaris-ccd plus optical spectrometer.

Schlüsselwörter

  • turning dynamometer
  • temperature and cutting forces
  • stainless steel
Uneingeschränkter Zugang

Semi-Markov Model of Quality State Changes of a Selected Transport System

Online veröffentlicht: 08 Nov 2019
Seitenbereich: 141 - 148

Zusammenfassung

Abstract

The study deals with the problems connected with evaluation and analysis of transport systems operational quality. The research object is a real, sociotechnical system (of the type H-M-E) whose functional quality is affected by: operators, equipment and technical state of he operated vehicles and the environmental impact. A scheme of an assessment model was built on the basis of a developed concept of a system operational quality and a random process was defined to be used for the analysis. The assessment process involves investigating the variability degree of properties included in the resultant model in a given time and determining whether and to what degree the obtained values meet the requirements of the system appropriate operational quality. On the basis of the above assumptions and in result of experimental tests, four qualitative states of a transport system functioning, which represent intervals of values of the obtained grades in given time moments, were distinguished. The study presents a model of system operation qualitative state changes developed with the use of Markov chain inserted into a certain semi-Markov process. A graph and a matrix for probability of transition between the states were created and boundary distributions of the process were determined on the basis of experimentally obtained data. A system of equations was determined for the distinguished Markov chain, on the basis of which a mathematical model for assessment and control of operational quality of selected types of transport systems will be built.

Schlüsselwörter

  • transport system
  • efficiency
  • operation and maintenance process
  • semi-Markov process
  • simulation tests
Uneingeschränkter Zugang

Simulation Studies of Hybrid Powertrain for Urban Vehicles

Online veröffentlicht: 08 Nov 2019
Seitenbereich: 149 - 156

Zusammenfassung

Abstract

The powertrain of an urban vehicle was subjected to detailed simulations. This study was conducted with the aim of getting to know the operating principle, verification of assumptions adopted during its design and determination of most effective control procedures to be applied with regard to its powertrain. However, the most important aspect involved the aspect of the power distribution between the engines, electrical machine and vehicle wheels in the particular operating modes of the powertrain. A study was conducted in the MATLAB/Simulink environment with the purpose of finding a configuration of an electrical machine coupling with a combustion engine that offers the greatest advantages in terms of the range of the speed ratio, demanded performance of the electrical machine and maximum power output. The simulations indicated that control of the speed ratio of the vehicle could be gained by application of an electrically controlled planetary gear. The range of the transmission ratio is relative to the ratio of the planetary gear, speed range of the combustion engine as well as electrical machine. The efficiency of the battery charging in the hybrid mode is mostly relative to the operating point of the engine. The optimization of the process of power generation by the electrical machine requires that the operating point of the engine be maintained at a range at which its high performance is guaranteed.

Schlüsselwörter

  • hybrid drive
  • electrically controlled planetary gear
  • integrated control
Uneingeschränkter Zugang

The Study on Algorithm for Identification the Fatigue Crack Length of Compressor Blade Based on Amplitude-Frequency Resonant Characteristics

Online veröffentlicht: 08 Nov 2019
Seitenbereich: 157 - 164

Zusammenfassung

Abstract

The article is focused on building the algorithm for identification the fatigue crack length in the first stage of compressor blade of the helicopter PZL-10W turbo-shaft engine. The fatigue wear of compressor blade is a process in which the fatigue crack begins at the structural notch of the working part. For compressor blade, the crack starts at the leading edge and progress along the blade chord. Due to working conditions, the compressor blades are referred to as critical components. The helicopter rotor downwash can easily lift particles form the ground that may cause damages in the compressor section. Aircraft engines are designed so that the rotational speed of impeller remains below the resonant frequency. However, the pulsation of working medium or mechanical vibrations may cause temporary increase of vibration frequency. The appearance of structural notch combined with temporary increase of vibrations may initiate the fatigue failure. The works undertaken at the Department of Aircraft and Aircraft Engines, Rzeszow University of Technology provided a wide spectrum of research data of amplitude-frequency (A-F) characteristics of 1st stage of compressor blade. For different crack lengths, the fatigue tests of resonant frequency and asymmetry of A-F characteristics were acquired. The crack lengths were measured by fluorescent or infrared mapping method. The aim of the article is to develop the numerical method for identification of crack length of compressor blade basing on A-F characteristics. The studies on A-F characteristics in order to find correlations between crack length, resonant frequency and characteristics asymmetry were performed. The next step was to build the algorithm for identification the crack length when only A-F characteristic is known. The article contains the description of researches background, A-F characteristics unique features, algorithm detailed methods of work and sample use of algorithm in identification the crack length.

Schlüsselwörter

  • fatigue failure
  • crack length
  • compressor blade
  • aircraft engine
  • failure identification algorithm
Uneingeschränkter Zugang

Automation of Training Methods and Judging of Aerobatic Flights

Online veröffentlicht: 08 Nov 2019
Seitenbereich: 165 - 171

Zusammenfassung

Abstract

The article presents the specificity of aerobatic operations that use on-board transmitters to improve the quality of training and judging in this sport area. The first chapter of this work is an introduction to the topic under discussion and the second chapter describes the principles of aerobatic competitions, methods of judge evaluations and the regulations related to the correctness of the figure performance by the pilots. The third chapter contains information on the AeroSafetyShow Demonstrator+PL system (ASSD+PL) used to carry out active supervision over flights in general aviation (especially in gliders and airplanes aerobatic). In the fourth chapter of the article, the possibilities of application of the ASSD+PL system functionalities were described which could improve the quality of training and judge evaluations. The Polish measurement system is actually an only electronic system, which is accepted and respected by the aerobatic judges all over the Europe. Functionalities of the ASSD+PL are used by them to control and sum up all the forbidden crosses the box. The pilot flying too low can be even disqualified. Application interface can be also transmitted in the real time to the big screen as well for the judges, as for the wide spectators watching the competitions flights.

Schlüsselwörter

  • aerobatics
  • aerobatic training
  • aerobatic judging
  • on-board transmitters
  • supervision system
Uneingeschränkter Zugang

The Fourier Transform as a New Approach of Evaluating the Internal Combustion Engine Indicator Diagram

Online veröffentlicht: 08 Nov 2019
Seitenbereich: 173 - 180

Zusammenfassung

Abstract

In this paper, the authors present an introduction to the new method of evaluating the indicator diagram of internal combustion engine. For several years, it was observed that analyses of combustion processes have been hardly changed since they were conducted for the first time. At the moment, the diagrams are plotted more and more precisely owing to the new sensors and digital processors. Despite all of these high technical advantages, which were obviously unavailable in the past, theoretical approach for describing indicator diagram has not changed in significant way. Nowadays, the indicator diagrams are still evaluated very generally and are presented in much too idealistic way as a smooth curve of pressure changes, without any disturbances, which are being detected very easily now. Furthermore, it appears that performance improvements of the IC engines are in need of developing new methods for analysis and evaluation. The Fourier transform is a new way to look at the combustion process in the engines. It is basically a mathematical instrument for analysing different types of signals, which are transformed, from time domain into frequency domain. It enables identifying specific sinusoidal components of arbitrary signals and separates relevant ones from the noise. This allows one to see significant differences in two or more apparently similar signals and detect the crucial parts. If we treat pressure changes in time like a common signal, we can compute Fourier transform and see basic components of the diagram.

Schlüsselwörter

  • indicator diagram
  • Fourier transform
  • internal combustion engine
Uneingeschränkter Zugang

Testing of Internal Combustion Engines of Motorcycles with the Use of Thermal Imaging Methods

Online veröffentlicht: 08 Nov 2019
Seitenbereich: 181 - 186

Zusammenfassung

Abstract

The internal combustion engine should be rated for the thermal loads that come from different sources. Thermal analysis is important both for design purposes and for evaluating the conditions of its use. Very good results are obtained by a combination of non-invasive measurement techniques, such as research using infrared thermal imaging techniques [3, 11]. The purpose of the study was to determine the engine thermal load by evaluating the average temperature on the outside surface of the engine at many of its points for two selected motorcycle engines with similar displacement capacities.

For many reasons, such as ecology, durability, engine strength and thermal performance when heating and cooling are critical. To accomplish this task, a thermographic technique for indirect evaluation has been used, thus creating the possibility of measuring the temperature in a dynamic manner. These are accurate measurements and most importantly do not interfere with the construction of the object under investigation. The engine was tested during operation according to external and load characteristics. As a result of the work, graphs of temperature curves of heating and cooling of the tested engines were compiled. The article presents a methodology for measuring the temperature fields of outer surface engines. The collected material will be used in the future for studying the equable load on the cylinders, and as accurately as possible determine the conditions of movement such as power, revolutions, flow rates, temperatures and pressures.

Schlüsselwörter

  • combustion engine
  • thermal analysis
  • thermography
  • thermal research of motorcycles
Uneingeschränkter Zugang

Assessment of the Suitability of the Fuels with Component Power Engines

Online veröffentlicht: 08 Nov 2019
Seitenbereich: 187 - 192

Zusammenfassung

Abstract

The article presents the results of laboratory tests of selected properties of fuels available on the market and fuels with higher density component B100 obtained from rapeseed oil (10, 30, 50 and 100%). An analysis of the cetane number, viscosity, and weight of the ash remaining after combustion of fuel samples was made. It was found that the cetane number of pure biocomponent is higher than diesel oil of mineral origin and it slowly decreased along with a decrease in the Extras component. All tested samples of fuels have appropriate cetane number to power internal combustion engines with compression ignition. The viscosity of the fuel samples measured at a temperature of 30ºC increased along with an increase in the content of biocomponent and approached the limit values for fuels. According to the results presented by other authors in their studies ash mass decreased along with an increase in the content of the component. Only premium diesel showed less ash mass than other fuel. The study includes also the energy value and the calorific value of liquid fuels with addition of a biocomponent, which power diesel engines. The results of the tests indicate a slight decrease in the calorific value of the fuel along with an increase in the content of biocomponent, which does not affect the ability to power the engines. Laboratory tests have proved that use of methyl esters of fatty acids in diesel fuel is the right choice to power diesel engines.

Schlüsselwörter

  • transport
  • biocomponent
  • diesel
  • energy
  • calorific value
  • viscosity
  • cetane number
Uneingeschränkter Zugang

Assessment Method of End-of-Life Vehicles Recycling Network Efficiency

Online veröffentlicht: 08 Nov 2019
Seitenbereich: 193 - 201

Zusammenfassung

Abstract

Recycling is a final stage closing the life cycle of vehicles. The quality of this process affects the combined impact of automobiles on the environment. Recycling networks differ in the level of efficiency due to the differences in how the recycling system is organized, their environment, and the characteristics of the entities taking part in recycling process. The article presents an algorithm of a method for assessing the effectiveness of a vehicle-recycling network, which can be used in a comparative analysis of networks, or for evaluating changes over time. A set of indicators relating to the technical, economic, environmental, and social aspects was proposed.

The article presents the variety of aspects involved in assessing, the efficiency of a vehicle-recycling network the best solution seems to be the inclusion of selected indicators for the assessment model, which will also act as a tool to assess the state of the network and conduct rankings of available solutions. The model for assessing the efficiency has to be preceded by determining the purpose and scope of the assessment and analysis of available evaluation tools.

Schlüsselwörter

  • recycling network
  • end-of-life vehicles
  • system efficiency
  • indicators
Uneingeschränkter Zugang

Diagnostic of the Piston Rod Gland’s Failure of Marine Slow Speed Main Engine

Online veröffentlicht: 08 Nov 2019
Seitenbereich: 203 - 210

Zusammenfassung

Abstract

The article presents untypical diagnostic of the slow-speed, marine main engine. The engine was newly made-up and checking during mounting process and during sea trial. However, a leak under piston chamber of second cylinder along the piston rod appeared few days after the sea trial. The stuffing box exchange (with the piston rod’s regeneration) did not give expected results − the failure happened again. All geometrical and exploitation parameters was in acceptable range. The ship with main engine was fifth in the series of sister ships. The authors were asked for urgent expert opinion. Mix of different measurements was planned after formulation several hypothesis. Displacements of piston rod and cylinder, a stress level of main engine body, and vibrations level in different points of main engine was performed during short sea voyage. Not a single hypothesis can be considered as the main cause of the failure. It turns out, that a serious failure need not be caused by a single reason. According to snowball theory a sum of small effects, each of them affecting slightly the engine operation, can be a cause of serious failure. In the authors’ opinion, the failure was caused by a sum of relatively slight effects. The probably scenario of the failure process was enunciated. The recommendation for the engine project was formulated: some of the geometrical tolerances should be changed.

Schlüsselwörter

  • marine propulsion systems
  • slow-speed main engine
  • failure of piston-crankshaft system
  • diagnostic based on vibrations
  • displacements and stresses level
Uneingeschränkter Zugang

Using Fuzzy Logic Expert System for the Estimation of the Probability of Armour Penetration by PGU-14 Shells Fired from the GAU-8/A Cannon

Online veröffentlicht: 08 Nov 2019
Seitenbereich: 211 - 218

Zusammenfassung

Abstract

The article discusses the possibility of armour penetration by PGU 14 API shells fired from the GAU-8/A cannon. The considerations focus on questions with regard to the probability of armour penetration with the initially established conditions in the project. In the analysis, the authors took into account three parameters: armour thickness, armour slope and target distance. Based on the initial parameters, the authors estimated the probability of armour penetration. The designed a fuzzy expert system in the MATLAB software as well as conducting simulation of its performance in the Simulink programmes. The authors presented the performance of the system based on twenty samples for research, which simulate different thickness of the target armour, different distance from the target and different slope of the armour. The authors presented control surfaces, due to which it is possible to analyse the system performance. They also show the simulation process in the Simulink software package with the preset values. On the basis of the created controller, it is clear that a well-developed system, which had undergone testing and optimization, is capable of calculating near reality probability values. The designed system might improve fire effectiveness of ground targets during air training and combat tasks, as well as optimizing the consumption of air-to-ground armour piercing (AP) shells.

Schlüsselwörter

  • fuzzy logic
  • fuzzy expert system
  • armour penetration
  • GAU-8/A cannon
  • PGU 14 API shells
Uneingeschränkter Zugang

Influence of Effectiveness Speed in Mechanical Properties of AW6060 T66 (PA38) Alloy

Online veröffentlicht: 08 Nov 2019
Seitenbereich: 219 - 226

Zusammenfassung

Abstract

The article examines the effect of the change in the speed of deformation on the mechanical properties of AW 6060 alloy specimens, characterized by high mechanical strength, which is a material used in the shipbuilding industry. The theoretical basis for the influence of load speed on the mechanical properties of materials is presented. Static and dynamic tensile test was conducted on a universal testing machine. Dynamic stretching was performed on samples at 10−1 s−1 – 102 s−1. Done charts and tables showing results. Calculated in accordance with DIN EN ISO 6892-1 2010P total elongation and contraction of the sample. Comparison of the results of the study with the current knowledge of the subject. Material studies have shown that increasing the deformation rate results in an increase in the yield point and tensile strength. On the basis of calculations of the narrowing and elongation of the total sample, the material can be strengthened. The rate of deformation of the materials is favourable for their strengthening by increasing the limit of tensile strength. Given that most of the design is subject to dynamic loads and the aluminum alloy AW 6060 finds extensive use in shipbuilding and beyond, these are satisfactory results.

Schlüsselwörter

  • alloy aluminum
  • static load
  • dynamic load
  • yield strength
  • strength limit
Uneingeschränkter Zugang

Modelling of the Influence of Tire Characteristics on Stability of Motion with Using Vehicle at a Scale

Online veröffentlicht: 08 Nov 2019
Seitenbereich: 227 - 237

Zusammenfassung

Abstract

The use of physical models of vehicles, at a scale allows them to be used when measuring the behavior of the full-size vehicles. The characteristics of the various systems and their impact on the dynamics of motion of the vehicle can be determined during stand tests or simulation and confirmed during testing of vehicles on test tracks. Testing vehicles built in small series, oversized or performed individually are conducted infrequently or not at all. In such cases, the alternative may be conducting tests of vehicles carried out at a scale. Research may be conducted in the boundary conditions (which could lead to loss of stability or overturning of the vehicle) impossible to achieve during testing of actual vehicles. They are particularly useful for assessing the stability of vehicles, the impact of the solutions or actions of a driver assistance system. Conducting research vehicles at a scale for the assessment of full-size vehicle must meet the criteria of similarity in the study of physical models of vehicles. One of the major issues is interaction of wheels and road. This article describes the results of wheels interaction with the road for tires with different characteristics used in the mobile model of the car and on the actual vehicle. The aim of the study was to prepare reference material to determine the correlation between the characteristics of the tire model and the full-scale tires. This will allow for made adjustment resulting from the impact of the characteristics of the tires on the motion dynamics of comparable cars especially in the curvilinear motion.

Schlüsselwörter

  • stability of vehicle motion
  • testing vehicles in scale
  • tires characteristics
Uneingeschränkter Zugang

Numerical Research of Toothed Gears Geometry Influence on Power Transmission System Vibroactivity

Online veröffentlicht: 08 Nov 2019
Seitenbereich: 239 - 246

Zusammenfassung

Abstract

The article presents results of numerical studies on the influence of selected factors on the dynamic effects and vibroactivity in power transmission system with toothed gear. Optimization of the constructions of the toothed gears is in many cases only possible by applying the numerical methods. Dynamic models allow determining the influence of a range of factors on the dynamic phenomena occurring during work of toothed gear. The studies were performed with use a custom developed dynamic model of a test stand with the gears operating in the circulating power system. It was assumed, that properly defined and identified model can be used to analyse dynamic phenomena occurring in meshing and bearings of toothed gears and allows optimizing their construction, especially allows minimization their vibroactivity. Numerical calculations were based on two sets of input data. Sets of input data consist information on all parameters included in the model, and which were determined during the identification process carried out in laboratory at two test stands. Selected results of simulations presented in this article prove, that identified dynamic model can be used to analysis of the impact of various constructional, technological and operational factors on the vibroactivity of the toothed gear.

Schlüsselwörter

  • power transmission system
  • toothed gear
  • dynamic model
Uneingeschränkter Zugang

Influence of Toothed Gear Geometry Parameters on Power Transmission System Vibroactivity

Online veröffentlicht: 08 Nov 2019
Seitenbereich: 247 - 254

Zusammenfassung

Abstract

The article presents selected results of experimental studies on the influence of chosen factors on the dynamic effects and vibroactivity of toothed gears in power transmission systems. The studies were performed on test stand with the gears operating in the circulating power system. On initial phase of the research, four pairs of helical gear wheels with the same value of gear ratios were designed and manufactured. The wheels differed by values of transverse contact ratio εα, face contact ratio εβ and total contact ration εC. In the research, the transverse vibration velocities of the shafts and housing of the tested toothed gear on FZG test stand was assumed to be the vibroactivity criterion. The measurements of the vibrations were carried out on the shafts and at seven points of the top plate of the housing. The vibrations were measured using a laser vibrometer and acceleration sensors. In addition, selected experimental results of measurements were compared with results of numerical simulations. To the simulations was used extended, identified dynamic model of the FZG test stand. The parameters of the wheels and the measured deviations were introduced into model. Obtained results confirm that by increasing the value of the contact ratio of the helical gear is possible reduction of dynamic phenomena occurring in the toothed gear.

Schlüsselwörter

  • power transmission system
  • vibroactivity
  • toothed gear
Uneingeschränkter Zugang

Use of Regression Analysis for Comparative Evaluation of Accident Hazard in Poland, by Regions

Online veröffentlicht: 08 Nov 2019
Seitenbereich: 255 - 264

Zusammenfassung

Abstract

Calculations carried out made it possible to characterize changes in the accident hazard, in numerical terms, based on the course of the regression line. An analysis of the distribution, by regions, of the accident hazard and, above all, the showing of changes in this hazard is an important contribution to the actions taken to improve the road transport system. The rate of decrease in the number of accidents undergoes changes, which are particularly conspicuous in some voivodships (provinces) against the background of the general process of decline in the nationwide number of accidents. A graph to characterize this hazard has been presented, plotted with taking into account the changes in the number of accidents, recorded in monthly steps for a period of 7 years. The rate of these changes was also evaluated, in medium-term and short-term intervals. The calculation results were used to ascertain whether a decline in the total number of accidents in Poland is accompanied by similar changes taking place in individual regions. The symptoms of increasing share of the number of accidents that occur in a few regions in the total number of accidents taking place in Poland may be a cause for alarm.

Schlüsselwörter

  • regression analysis
  • road accidents
  • accident hazard by regions
Uneingeschränkter Zugang

Airfoil Selection for Wing in Ground Effect Craft

Online veröffentlicht: 08 Nov 2019
Seitenbereich: 265 - 269

Zusammenfassung

Abstract

The main purpose of this article was to select airfoil, which generates the biggest lift coefficient, with possibly smallest drag coefficient when the airfoil flies in the wing in ground effect. Wing in ground effect occurs in the direct proximity of ground, the article presents wing in ground effect creation mechanism description with automotive and aerospace examples.

The article shows also wing in ground conditions of Ansys Fluent software simulation for all cases with conditions of analysis convergence. The article contains results of the numerical analysis for ten airfoils in three different positive angles of attack in the wing in ground flight; ten airfoils for free stream flight in the same angles of attack as in wing in ground effect, results contains lift and drag coefficients with NACA M8 airfoil presentation as authors choice for wing in ground effect crafts airfoil with full simulation results for angles of attack from –5° to 15°, with profile characteristics.

The article shows physics of stall in the wing in ground effect, and a description why stall in WIG effect flight occurs only with drag coefficient rise without lift coefficient drop, and safety measures for aircraft landing with wing in ground effect influence.

Schlüsselwörter

  • transport
  • ekranoplan
  • numerical analysis
  • wing in ground effect
  • airfoil
Uneingeschränkter Zugang

Evaluation of Transmission Secure Methods in its Systems

Online veröffentlicht: 08 Nov 2019
Seitenbereich: 271 - 278

Zusammenfassung

Abstract

The essence of the operation of all ITS systems is to make decisions based on the information obtained and available. Under these assumptions, these systems are expected to utilize telecommunication, IT, automation and measurement technologies, which, in conjunction with advanced control methods, improve communication. Each ITS subsystem has specific requirements for communications channels that have to be tailored to the needs of the subsystem, its topology, and users, taking into account the costs of both the construction and operation of the system. The article presents issues related to information security analysis in ITS systems. Some selected aspects of risk prevention, which may be an important factor affecting the safety of the transport system, will be analysed. The analysis and evaluation of secure data transmission methods will also be conducted. This analysis and evaluation will select secure transmission methods using VPN virtual tunnelling technologies.

In the article, the selected problems related to the security and confidentiality of information transmission between ITS elements and the provision of protecting access to the IT systems’ resources and their stored data, the aspects of problem affecting the communication system architecture is signalled. The methods for secure transmission in ITSs are secure transmission methods commonly used in systems, which require the confidentiality and security of information transmission between the data source and its recipient.

Schlüsselwörter

  • transport
  • ITS systems
  • security
  • information
  • threats
  • technologies
Uneingeschränkter Zugang

Modelling and Numerical Analysis of Explosion Underneath the Vehicle

Online veröffentlicht: 08 Nov 2019
Seitenbereich: 279 - 286

Zusammenfassung

Abstract

The article presents a method for numerical modelling of interaction of a shock wave on a simplified model of a light armoured vehicle. Detonation of the explosive material occurs centrally underneath the vehicle. The mass of an explosive charge was from 0.5 to 10 kg off TNT. Acceleration, displacement and kinetic energy of the floor plate/panel were verified during the tests.

The model and numerical calculations were carried out using the following programs: CATIA, HyperMesh, LS-PrePost, LS-Dyna. CONWEP approach was applied to describe interaction of a pressure wave on the structure. For each case, the explosive charge was located at the same place under 700 mm from the top surface of the range stand. The results of the calculations present the effects of detonation under the vehicle without a protective system and with the protective system. The proposed protection system is made of low-density materials such as aluminum foam and cork. Thanks to such an approach, the effectiveness of the protective system will be checked to reduce the adverse physical quantities that threaten the health of the soldiers. Thanks to very simple solutions, it is possible to increase passive safety of passers and use of low-density materials will slightly increase the vehicle’s mass leaving manoeuvrability at a similar level.

Schlüsselwörter

  • shock wave
  • LightArmoredVehicle (LAV)
  • CONWEP
  • protective structure
  • IED
Uneingeschränkter Zugang

Design and Optimisation of Main Rotor for Ultralight Helicopter

Online veröffentlicht: 08 Nov 2019
Seitenbereich: 287 - 295

Zusammenfassung

Abstract

A modern main rotor, dedicated to the ultralight helicopter, has been designed and optimised. Due to assumed simplicity of the rotor design and taking into account some technological constraints, the principal purpose of the presented research was to design a dedicated airfoil which, when applied on the main-rotor blades, would influence satisfactory improvement in a performance of the ultralight helicopter, especially in fast flight. The design and optimisation process has been supported by a computational methodology. The in-house software has been used for direct and inverse design of shapes of the rotor-blade airfoils. Aerodynamic properties of the airfoils as well as the helicopter main rotor were evaluated based on both the two-dimensional and three-dimensional flow simulations conducted using the ANSYS FLUENT software that was used to solve U/RANS equations. Based on the results of conducted computational simulations of fast flight of the ultralight helicopter, it can be concluded that the newly designed main rotor, compared to the baseline, may give certain improvement in helicopter performance in fast flight. In addition, the application of this newly designed rotor may lead to increase of a maximum speed of the helicopter flight, due to the greater lift force achievable by this rotor on the retreating blade, which is favourable from point of view of keeping of a lateral balance of the helicopter in fast flight.

Schlüsselwörter

  • rotorcraft
  • ultralight helicopter
  • main rotor
  • airfoil
  • computer-aided design and optimisation
Uneingeschränkter Zugang

Burnishing Treatment of the Faying Surface of the Pipe Flange

Online veröffentlicht: 08 Nov 2019
Seitenbereich: 297 - 303

Zusammenfassung

Abstract

On ships for connecting pipes in seawater installations, fire and other installations and for joining pipes to fittings or receivers, flange-type couplings are often used. It is important to ensure tightness between pipe flanges (ASME). If the system pressure does not exceed 1.6 MPa, “open” flange packing using flat gasket rings is used. Rubber, textolite, polyvinyl chloride or metals and alloys with good plastic properties (e.g. aluminum, copper, Monel alloy, Armco iron) can be used as a sealant material (depending on pressure in installation). The tightness of the joint determines the quality (geometric structure) of the surface of the flange at the contact point with the gasket. Reduced roughness ensures even distribution of surface mounting pressures on flange joint gasket. This article deals with the assessment of the use of burnishing as a finishing treatment for flange faces and the selection of rolling parameters. Samples used for the tests were made of S235J2 carbon steel. Burnishing treatment was done with the SKUV20 tool. The working element of the tool was in the shape of a roller. Burning was performed using the following parameters: the burnishing force (Fn) – 600 N, 800 N and 1000 N; Feed rate (f): 0.08 mm/rev, 0.13 mm/rev, 0.24 mm/rev; the speed of burnishing (vn) – for a diameter of 55 mm – was 45 m/min, 65 m/min, 78 m/min. The research was carried out on the basis of trivalent plan Hartley. As the output variables (dependent variables), the roughness reduction index (KRa) and the (Su) were adopted. Based on the multiple regression analysis, it was found that the greatest impact on reducing roughness and surface hardening of burnished material has burnishing force. The dependence between dependent variables and Fn is proportional. The effect of the burnishing speed (vn) on the values of KRA and Su parameters is statistically insignificant. Machining of the active surface of the pipe flanges should be carried out with a burnishing force of 1 kN, a feed rate of 0.08 mm/rev and a burnishing speed of 45 m/min.

Schlüsselwörter

  • burnishing
  • pipe flange
  • flange face
  • roughness
  • multiple regression
Uneingeschränkter Zugang

The Analysis of the Properties of Ablative Composites with Carbon and MMT Nanofiller Reinforcement

Online veröffentlicht: 08 Nov 2019
Seitenbereich: 305 - 312

Zusammenfassung

Abstract

One of the most important parameters in the selection of composite materials used for the protection of avionics instruments exposed to high temperatures are ablative properties. They constitute the main criterion in determining the composition and thickness of the protective material. In this article, the authors determine the ablative properties of a polymer matrix with carbon reinforcement and check the effect of using the MMT additive (montmorillonite) on the change in the resistance to the impact of a high heat flux. The tested materials play an important role in the defence, aviation and space industry. Ablative materials are the only ones to protect the rear wall surface from an excessive temperature rise while using a thin insulation wall. For the sake of the research, we prepared a series of samples of the composite produced with epoxy resin LH 145, H 147 hardener, carbon fibre mats and the addition of MMT. The prepared samples were tested on a unique stand in laboratory conditions. The findings obtained from the experimental testing after a detailed analysis were tabulated and presented in the form of graphs. The authors determined the ablative loss of mass of the individual samples, compared their internal temperatures, which had been measured with thermocouples, as well as the temperature on the backside of the sample. In addition, in order to complement the experimental studies of determining the temperature rise on the rear surface, the authors used a thermal imaging camera. Besides, they took photos of different layers of the examined structure, which had been exposed, to a heat stream, by means of a scanning microscope.

Schlüsselwörter

  • composite
  • ablative properties
  • nanotubes
  • carbon fibre
  • ablation
Uneingeschränkter Zugang

Analysis Concerning Changes of Structure Damping in Welded Joints Diagnostics

Online veröffentlicht: 08 Nov 2019
Seitenbereich: 313 - 320

Zusammenfassung

Abstract

Among non-destructive testing methods of welded joints, a vibrodiagnostic method is one of the most promising in applications intended for the continuous monitoring of the structure. The accelerometer-recorded responses provide diagnostic information that requires mathematical processing to extract the essential features typical of the tested welded joints and to evaluate their execution. For this purpose, the proposed method was based on the determination of damping decrement in function of time. Due to the complexity of the responses run, a proposed method consisted of calculating the damping decrement using the response approximation with different functions. It has been shown that the changes analysis of damping decrement applied to welded plates enables the assessment of the quality associated with the weld. Attention was also paid to the elements relevant to the study. This work presents the algorithm and exemplary results obtained from the application of proposed method to several selected sample plates with different type of welds. A scientific apparatus, which purpose was to record dynamic characteristics of welded joints was also described.

Schlüsselwörter

  • diagnostics
  • welded joints
  • non-destructive testing
  • NDT
  • SHM
  • vibration
  • spectrum analysis
  • damping decrement
Uneingeschränkter Zugang

The Conception of Modular Monitor of Car Exploitation Parameters

Online veröffentlicht: 08 Nov 2019
Seitenbereich: 321 - 326

Zusammenfassung

Abstract

Current tendencies in electronics and informatics development going towards Internet of Things (IoT), Big Data or Data Cloud technologies create new possibilities in acquiring and utilizing data. The article presents the concept of modular monitoring of vehicles operating parameters. Presented device registers data from the OBD system and a set of independent, configurable sensor modules. Data from the OBD system is acquired via protocol. CAN Bus with a DLC connector. The signal from sensor modules is transferred via a Bluetooth wireless network. The registered data can be storage on board as CD card memory or alternatively on a typical user interface such as laptop, tablet, cell phone etc. The communication with the user interface is realised with USB. Moving vehicles modular monitoring system presented in the article can be used to attain a fuller representation of the vehicles state in relation to its environment. The base assumption of the device is maximal flexibility in term of sensors versality as well as possibilities of assembly on board. In connection with the concept, a prototype of the device was made and tested with an inertial measurement unit (IMU) module and a pressure sensor. Appliances modules are based on Cortex M4 and M0 processing units. A users interface in LabVIEW and examples of registered signals are showed at the end of the article.

Schlüsselwörter

  • automotive
  • communication networks
  • car parameter monitoring
  • CAN
  • modular system
Uneingeschränkter Zugang

Use of 3D Printing Technology in the Aviation Industry on an Example of Numerical Experimental Stress State Analysis of Unmanned Aerial Vehicle Wing

Online veröffentlicht: 08 Nov 2019
Seitenbereich: 327 - 334

Zusammenfassung

Abstract

The article presents the results of static tests performed on the primary support structures of a TWISST-ter unmanned aircraft constructed using additive manufacturing techniques commonly known as 3D printing. The primary goal of the experiment was determining the material effort of the structure in order to assess the feasibility of such an engineering solution in terms of material mechanics. Considering the fact that the properties of 3D printed elements are not widely known, both destructive experimental methods and finite element methods were used. During the experimental trails, the ARAMIS deformation measurement system, based on digital three-dimensional image correlation, was used. The results of this experiment allowed for the calibration of the numerical model as achieving convergence with experimentally determined strain fields. This approach ensured the correctness of the numerical determined stress state. Based on the results of the study, the necessary design improvements were implemented and a general conclusion was formed regarding of the numerical analysis of structures made through 3D printing.

Schlüsselwörter

  • DIC
  • 3d printing
  • FFF
  • stress state
  • UAV
Uneingeschränkter Zugang

Geometrical Structure for Endoprosthesis Surface Lubrication and Wear Prognosis

Online veröffentlicht: 08 Nov 2019
Seitenbereich: 335 - 341

Zusammenfassung

Abstract

It can be stated that over the last ten years in the European Union, the number of bone fractures caused by osteoarthritis has increased twofold. More than 100,000 hip or knee joints in total were implanted in Germany during one year. Within ten years, 5% of them have failed by aseptic loosening. The non-invasive determination of friction forces and control of their values during lubrication of cartilage cells on the superficial layer of human joint surfaces before implantation has a significant but not sufficient impact on the observation of the early abrasive wear of the cartilage joint and development of osteoporosis. From this fact was drawn the inspiration for the performed investigations related to the endoprosthesis surface parameters because knowledge of the roughness of prosthesis surfaces and friction forces and their control methods permits provision of a necessary standard deviation of the gap height and finally information about the implantation possibility. This article has been prepared based on the objective of European Project UE Grant IRSES,612593, 2013-2016 to represent the methodology and goal of the idea described in and make a wider discussion possible on this subject for further developments during the realization. To the research methods and materials used in this article realization belong: Rank Taylor Hobson-Talyscan 150 Apparatus implemented by Talymap Expert and Microsoft Excel Computer Program connected with the Mathcad 15 Professional Program and a new semi-analytical methods of probabilistic and statistic prognosis applied for theory of hydrodynamic lubrication of the curvilinear orthogonal surface and coordinates extended to the friction and wear problems of the endoprosthesis surfaces during the exploitation.

Schlüsselwörter

  • endoprosthesis
  • surface
  • measurements
  • gap height
  • wear
  • random prognosis
Uneingeschränkter Zugang

Research on Composite Materials in the Institute of Aviation

Online veröffentlicht: 08 Nov 2019
Seitenbereich: 343 - 348

Zusammenfassung

Abstract

This article contains information on new duties of Centre for Composite Technologies (CCT) managers, implemented to increase their efficiency. Methods of quality improvement of aeronautical composite materials testing are presented. It was achieved by correct test plans definition, performing mechanical and physicochemical tests up to allowable composite generation. Several tests of this type are listed which are executed according to international standards of American Society for Testing and Materials (ASTM), including those in extreme temperatures. Effect of Lean Sigma and DMAIC (Define, Measure, Analyse, Improve, Control) implementation in the lab of CCT is shown. Results of bearing strength of quasi-isotropic laminate (carbon fibre and epoxy resin) with a bolt in different ambient conditions are presented. Moreover, the article discusses methodology of tension and shearing strength determination in the case of composite specimens diverging from others with application of statistical MNR method (Maximum Normed Residual). MNR coefficients are then compared with Critical Values.

Schlüsselwörter

  • composites testing
  • carbon-epoxy pre-impregnates
  • Maximum Normed Residual
Uneingeschränkter Zugang

Gyroplane Rotors Vibration Tests

Online veröffentlicht: 08 Nov 2019
Seitenbereich: 349 - 354

Zusammenfassung

Abstract

The article presents vibration test of three different types of gyroplane main rotors. The test was carried out on a specially prepared test bench using a Red Led Tacho Sensor measuring system. Tests were conducted for the project „Research and development works on innovative construction of aircrafts of weight over 560 kilograms at the company Trendak Aviation”. The work outlines the basic properties of the gyroplane vibration and gives their sources. The research focused on the gyroplane main rotor vibration related inter alia to the rotor imbalance as well as rotor hub connector construction. Tested rotors consisted of three different types of gyroplane rotor blades and innovative universal hub connector with positive coning angle of 2.8º. The article summarized the basic properties of three types of gyroplane the rotor blade, marks advantages of use hub connector witch constructional dihedral angle. Discusses the principle of operation of measuring device, tests methodology starting from instrument calibration. The results of the measurements are shown in the graphs in polar coordinates. The vibration measurement is carried out in two axes, in x-axis, longitudinal, along the rotor radius and in y-axis, perpendicular to the x-axis, in the direction of the chord of the rotor blades.

Schlüsselwörter

  • rotor vibration
  • rotor blades
  • teetering rotor
  • hub connector
  • rotor imbalance
Uneingeschränkter Zugang

Evaluation of Operational Availability of Municipal Transport System

Online veröffentlicht: 08 Nov 2019
Seitenbereich: 355 - 361

Zusammenfassung

Abstract

The primary subject of research is the procedure leading to safe, efficient, reliable and timely completion of transport tasks. The tasks, assigned to the transport system, are carried out by an operative subsystem, comprised of elementary subsystems of the man – technical object (operator-vehicle) type. The timely and safe completion of the tasks is influenced by the level of availability and reliability of elementary subsystems. Those in control of the process of the use of means of transport (vehicles) should undertake control decisions in such a way that would correctly evaluate the efficiency of process completion. In the area of public transport, technical availability of buses constitutes an important criterion of the evaluation of transport system. As a result, the transport company should provide continuous surveillance of the process of vehicle use in order to achieve running availability of the whole system. The requirements expected from devices and machines used head towards servicing via preventive method taking into account the technical condition of the system. Such an approach is a transformation towards technical system servicing process management. Correct completion of transport tasks is possible when the required traffic safety is met, taking into consideration the technical condition of the means of transport. The municipal transport systems should ensure the quality of the services provided to meet the expectations of the users. In the set of characteristics of the researched transport system, the following ones stand out: regularity, availability, reliability, course frequency, travel comfort, timeliness, speed, service complexity, competitive cost of transport service, and safety.

Schlüsselwörter

  • transport
  • road transport
  • simulation
  • combustion engines
  • air pollution
  • environmental protection
Uneingeschränkter Zugang

Aerodynamic Effect of Turbo Prop Engine Slipstream on Aircraft Tail Assembly Vibration

Online veröffentlicht: 08 Nov 2019
Seitenbereich: 363 - 367

Zusammenfassung

Abstract

The article presents a computational analysis of the effect of the turboprop engine slipstream on generation of aerodynamic forces induced vibrations of aircraft tail assembly (empennage). Working propellers exhaust system, engine nacelle, and wing-engine nacelle flow interference phenomenon can cause strong non-stationary disturbances behind the wing of the aircraft. These disturbances, propagating in the direction of the aircraft tail assembly, may be an important factor influencing the operation of the airplane flow control system and the source of aerodynamic forces generating vibrations of the entire plane structure. The article presents an example of analysis of this phenomenon for a light passenger-transport aircraft using advanced numerical models for simulation of the flow around the aircraft. In the computational model, Navier-Stokes flow equations were solved by finite volume method with the K-Omega SST turbulence model to calculate the turbulent kinetic energy distribution in the flow slipstream behind the airplane propulsion unit. The Ansys Fluent commercial solver was used to run analyses. To perform the simulation, high quality, dedicated conformal computational mesh, consisting of hexahedral and tetrahedral elements was prepared to evaluate the propagation of the flow disturbances with limited numerical dispersion effect. Mesh generation was conducted using Ansys ICEM CFD and Mesher software. Unsteady aerodynamic forces for horizontal and vertical tail-planes of the airplane were computed during simulations. Fourier analysis of the driven forces was performed, which resulted in finding the dominating vibration frequencies generated by the flow field around the tail assembly. The visualization of the flow field and the regions of the strong disturbances were presented. Results can be exploited in the pre-design process of aerodynamic configuration of multi-engine aircrafts.

Schlüsselwörter

  • air transport
  • aerodynamic wake
  • nacelle
  • tail assembly
  • vibration
Uneingeschränkter Zugang

Optimizing the Number of Docks at Transhipment Terminals Using Genetic Algorithm

Online veröffentlicht: 08 Nov 2019
Seitenbereich: 369 - 376

Zusammenfassung

Abstract

This article presents the issue of designating the number of docks at the transhipment terminals using genetic algorithm. Transhipment terminals refer to cross-docking terminals. The main factor that influences on the number of these docks is the stream of cargo flowing into the given terminal. In order to determine this flow of cargo the mathematical model of the distribution of this flow was developed. This model takes into account constraints like those that e.g. processing capacity at the transhipment terminal cannot be exceeded or demand of recipients must be met. The criterion function in this model determines the minimum cost of the flow of cargo between all objects in the transport network. To designate the optimal stream of cargo flowing into the transport network the genetic algorithm was developed. In this article, the stages of construction of this algorithm were presented. The structure processed by the algorithm, the process of crossover and mutation were described. In the article in order to solve the problem of designating the number of docks at the transhipment terminals the genetic algorithm was developed.

Schlüsselwörter

  • transhipment terminals
  • genetic algorithm
  • optimization
  • cross docking
Uneingeschränkter Zugang

A Method of Assessing the Tendency of Aviation Fuels to Generate Thermal Degradation Products Under the Influence of High Temperatures

Online veröffentlicht: 08 Nov 2019
Seitenbereich: 377 - 384

Zusammenfassung

Abstract

The subject of the article concerns the issues associated with thermal degradation of aviation fuels under high temperature conditions. Due to the intensive development towards increasingly higher thermal loads for both, turbine aviation engines, as well as the used fuels, the issue of thermal stability of the fuel itself is extremely important. In aviation, the fuel, apart from direct participation in energy generation during the combustion process of a fuel-air mixture, also takes part in the heat transfer in many aircraft systems. As a result, requirements in terms of the fuel’s thermal potential are increasingly higher. The standard method for determining the thermal stability of fuel executed on a JFTOT device proves to be insufficient in the context of the appearing issues in current operation. The article presents a non-standard approach to the assessment of aviation fuel thermal degradation with the use of a specialist test rig. The authors believe that the presented methodology and the measurement capabilities of the test rig are valuable supplementary material for the standardized thermal stability test. It allows more thoroughly understanding the phenomena undergoing in the fuel impacted by high temperatures. The article has been prepared within the research project no. 2011/01/D/ST8/06567 funded by the National Science Centre in Poland.

Schlüsselwörter

  • jet fuel
  • turbine engine
  • thermal stability
  • test rig
  • non-standard method
Uneingeschränkter Zugang

Application of Similarity Method of Distance Courses Describing the Elements Content in Concrete Intended for Airfield Pavements

Online veröffentlicht: 08 Nov 2019
Seitenbereich: 385 - 392

Zusammenfassung

Abstract

The work presents the applied similarity methods of distance courses in case of cement concrete intended for airfield pavements. Composition of concrete mixes was designed and their parameters were defined. Compressive strength of hardened concrete and components thereof and the occurrence of crystal phases were determined. Subject to observations of internal structure of concretes and conducted chemical microanalyses using scanning electron microscope, the contents of diversified elements in four zones were specified. Similarity indexes between input and target sequence were defined. Diagrams presenting the similarity of the analysed concretes were prepared. It was proved that the suggested method could be used to assess the elements content and define the similarity of concrete intended for airfield pavements. The scope of works consisted of two stages. During the first one, two series of cement concrete were prepared. The analysis included cement concretes intended for airfield pavements, in compliance with requirements. The influence of variable environmental conditions with respect to standard ones on the selected features of hardened concretes was assessed.

Schlüsselwörter

  • cement concrete
  • airfield pavement
  • analysis of similarity
Uneingeschränkter Zugang

Application of Similarity Method of Distance Courses Describing the Elements Content in Pavement Quality Concrete

Online veröffentlicht: 08 Nov 2019
Seitenbereich: 393 - 398

Zusammenfassung

Abstract

The publication presents the application of similarity analysis of distance courses. This method has been applied to define similarity of cement concrete intended for airfield pavements. The scope of works included standard concretes intended for airfield pavements and concretes after frost resistance test. The test has been conducted in diversified media used in the course of winter maintenance. The nature of resistance of pavement quality concrete was discussed with respect to frost resistance thereof. Research procedure was presented and the obtained laboratory tests results were discussed. Concrete samples were subject to observations using scanning electron microscope in order to define changes occurring in the internal microstructure. Chemical microanalysis of concrete composition before, in the course of and after the frost resistance test and the occurring changes were specified. The obtained laboratory tests results were intended for the purposes of the similarity analysis. Results obtained in case of standard pavement quality concrete were considered as comparative values. Characteristics of the remaining concretes were referred to these values and then similarity of distance courses were analysed. It was proved that BWMt concrete was the most similar concrete to the comparative concrete.

Schlüsselwörter

  • cement concrete
  • airfield pavement
  • analysis of similarity

Planen Sie Ihre Fernkonferenz mit Scienceendo