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 26 (2019): Heft 3 (September 2019)

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

Suche

33 Artikel
Uneingeschränkter Zugang

Comparison of Reduction Systems of Harmful Substances into the Atmosphere in Accordance to Requirements of IMO Tier III

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 7 - 14

Zusammenfassung

Abstract

Degradation of the environment is nowadays believed to be the most alarming problem that needs to be solved. Global warming and environmental pollution are predicted to cause a catastrophic chain reaction leading to species extinction, mass emigration due to rising sea levels and global crisis. The only solution suggested by international organizations is the immediate reduction of greenhouse gases and other harmful substances. Marine transportation harmful substances into the atmosphere are recognized to be a significant source of global atmospheric pollution. Despite the high efficiency of marine diesel engines, their impact on the environment is considerable. Due to environmentally friendly policies, modern engines concerns about not only efficiency but also mainly about s aspects. This article analyses and compares marine s exhaust gases reduction methods. Especially the most harmful substances emitted by ships were taken into consideration. The article presents the most crucial law regulations of harmful substances to the atmosphere, pointing at actual and possible future implementations. The most complex methods allowing meeting the latest limits were presented. Pros and cons of available control methods were thoroughly described and methods were compared. The most adequate methods form the effectiveness and economical point of view was pointed out.

Schlüsselwörter

  • NOx
  • SOx
  • MARPOL
  • atmosphere pollution
  • marine transportation
  • dual fuel
Uneingeschränkter Zugang

The Application of the BSSD Iono-Free Linear Combination Method in the Processing of Aircraft Positioning

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 15 - 21

Zusammenfassung

Abstract

The article presents the results of research into the use of the differentiation technique of BSSD (Between Satellite Single Difference) observations for the Iono-Free LC combination (Linear Combination) in the GPS system for the needs of aircraft positioning. Within the conducted investigations, a positioning algorithm for the BSSD Iono-Free LC positioning method was presented. In addition, an experimental test was conducted, in which raw observational data and GPS navigation data were exploited in order to recover the aircraft position. The examination was conducted for the Cessna 172 and the on-board dual-frequency receiver Topcon HiperPro. The experimental test presents the results of average errors of determining the position of the Cessna 172 in the XYZ geocentric frame and in the ellipsoidal BLh frame. Furthermore, the article presents the results of DOP (Dilution of Precision) coefficients, the test of the Chi square internal reliability test and the HPL and VPL confidence levels in GNSS precision approach (PA) in air transport. The calculations were performed in the original APS software (APS Aircraft Positioning Software) developed in the Department of Air Navigation of the Faculty of Aeronautics at the Polish Air Force University.

Schlüsselwörter

  • GPS system
  • aircraft positioning
  • BSSD Iono-Free linear combination
  • air navigation
Uneingeschränkter Zugang

The Physical Modelling of High Speed Broaching of the Heat-Resistant Steels for Studies Surface Layer Quality

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 23 - 29

Zusammenfassung

Abstract

The main idea of the work is to create a physical model of high speed broaching heat-resistant materials is used to study the parameters of the surface layer quality. Modelling is a method of mediated cognition, in which the object under study is in some correspondence with the model, and the object-model is capable in some way or another to replace the original at some stages of the cognitive process. Physical modelling is primarily distinguished by the fact that studies are conducted on models with physical similarity, i.e. preserving completely (or at least partially) the nature of the phenomena. The work of the broach can be likened to the work of a number of planning cutter displaced relative to each other by a small amount, which is called lifting (feed per tooth). Therefore, for experimental work, a planning cutter of a special geometric was designed and manufactured – a physical model of a broach, in which geometric, mechanical and dynamic similarity is realized. The article also presents an experimental justification for the use of the created physical model in the study of the surface quality parameters of the, tab grooves of turbine and compressors disks made of heat-resistant materials.

Schlüsselwörter

  • physical modelling
  • high-speed broaching
  • surface quality
  • tab grooves
  • heat-resistant steel
Uneingeschränkter Zugang

An Attempt to Reduce the Emission of Spark-Ignition Engine with Mixtures of Bioethanol and Gasoline as Substitute Fuels

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 31 - 38

Zusammenfassung

Abstract

Limiting emissions of harmful substances is a key task for vehicle manufacturers. Excessive emissions have a negative impact not only on the environment, but also on human life. A significant problem is the emission of nitrogen oxides as well as solid particles, in particular those up to a diameter of 2.5 microns. Carbon dioxide emissions are also a problem. Therefore, work is underway on the use of alternative fuels to power the vehicle engines. The importance of alternative fuels applies to spark ignition engines.

The authors of the article have done simulation tests of the Renault K4M 1.6 16v traction engine for emissions for fuels with a volumetric concentration of bioethanol from 10 to 85 percent. The analysis was carried out for mixtures as substitute fuels – without doing any structural changes in the engine's crankshafts. Emission of carbon monoxide, carbon dioxide, hydrocarbons, oxygen at full throttle for selected rotational speeds as well as selected engine performance parameters such as maximum power, torque, hourly and unit fuel consumption were determined.

On the basis of the simulation tests performed, the reasonableness of using the tested alternative fuels was determined on the example of the drive unit without affecting its constructions, in terms of e.g. issue. Maximum power, torque, and fuel consumption have also been examined and compared. Thus, the impact of alternative fuels will be determined not only in terms of emissions, but also in terms of impact on the parameters of the power unit.

Schlüsselwörter

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

Investigation of the Effect of Diamond Powder on the Thermal Properties of Octadecane Using Differential Scanning Calorimetry

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 39 - 45

Zusammenfassung

Abstract

The purpose of this work was to examine the effect of diamond powder on the thermal properties of phase change materials on the example of octadecane. The experiment involved mixing of diamond powder with a specific granulation with the aforementioned representative of the alkanes group. Two different grain sizes were used: 50 and 250 micrometres. The change of specific heat, latent heat of phase change and degree of supercoiling in newly formed mixtures was compared to the pure forms of the phase-change materials used. Initial mixing with a glass-stirring rod showed strong stratification for each granulation due to the low viscosity of the mixture and too large differences between component densities. It was decided to add amorphous silicon dioxide to the mixtures, which increases density of the mixture. The optimal percentage of amorphous silicon dioxide was estimated experimentally. Measurements of thermal parameters were carried out using DSC technology. The results of the tests of specific heat and latent phase transition heat showed that with the increasing content of diamond, the specific heat of the mixture decreases almost twice, and the latent heat can decrease by up to three times. The effect of diamond powder on reducing the degree of supercoiling of the mixture was also observed. An important observation was that the mixture with higher granulation of diamond powder had greater tendency for sedimentation. This method could be used to increase thermal conductivity and diffusivity of phase change materials and make them viable for use in systems that require cooling at high rate or temperature stabilization, such as control systems in electronic vehicles or aviation industry and at the same time decrease the degree of supercoiling which could increase the efficiency of system.

Schlüsselwörter

  • phase change materials
  • PCM
  • diamond powder
  • thermal conductivity
  • thermal diffusivity
Uneingeschränkter Zugang

Results from Laboratory Tests of New Electric Brake Prototype

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 47 - 52

Zusammenfassung

Abstract

The main idea of this article was to compare the results of new design electric brake to the older version of hydraulic brake in laboratory tests. The energy of braking should be very similar due to the same mass of the airplane. That is why the laboratory tests of both brakes were took place in the same stand. Of course, the parameters were similar but not at all. The main idea was to create the solution, which could be used in vehicle like airplane. The electric brakes could replace traditional hydraulic brake solution. The results could be interesting for every researcher who is interested in brakes. Other important idea of this article was to describe the tests of new electric brake prototype. The purpose of the tests was to check designing of electric brakes. The electric brake prototype should ensure sufficient efficiency, safety, reliability and durability during braking, which is required in certification processes and is particularly important when researching innovative solutions. It was really important to verify the design and check the parameters. Of course, there is really important to remember that in every new type of the prototype solutions there are many pros and cons, which are typical only for considered design. Nowadays every electric brake design is different because there is a lot of new concept.

Schlüsselwörter

  • laboratory test
  • electric brake
  • braking process
Uneingeschränkter Zugang

Overhead Travelling Crane Construction Deflection Measurements with Telematic Approach

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 53 - 60

Zusammenfassung

Abstract

Transport has always been a fundamental impulse for the development of civilization. Issues related to the regularity of operation of technical systems, in the last decade have become important issues being considered from both the point of view, as well as economics. Today the major threat in the operational reliability constitutes intensification of the machine and equipment use leading to excessive degradation. In automated manufacturing processes where the material handling operations are realized by the cranes, the safety as both devices and operating people constitute important factor. The main purpose of the article was focused on the set of issues including the material handling devices (MHD) reliability shaping problem especially presents work in progress towards development the MHD condition assessment system with using telematic approach. In the article author, special care was enclosed to MHD devices with strength human factor interaction and relatively large construction, so the overhead travelling crane was chose. The object of the statement constitutes an attempt of collecting the knowledge concerning a possibility of use modern measurement systems to monitoring crane bridge deflection. All tests and considerations were conducted on the double girder overhead travelling crane with hosting capability 1000 kg and bridge span 8000 mm.

Schlüsselwörter

  • crane bridge deflection
  • total station
  • telematics
Uneingeschränkter Zugang

Engine Cadets with and Without Additional Training on Training Vessel – Competences Comparison Case Study

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 61 - 68

Zusammenfassung

Abstract

In the last decade evolution of the requirements for training and professional competences of ship’s crewmembers, including ship engineers can be observed. Despite the implementation of training programs according to IMO requirements in maritime training centres, a different level of competence of young people beginning their professional career on ships in the engine department is observed. The article discusses general conventions, goals, and effects of the “BS Cadet Program” training program, introduced by one of the larger German ship-owner to improve the competencies of crewmembers at the operational level, who will take duties of the watch engineer in the ship engine room soon. General idea of this training program is reducing the time of the path career what is a standard in most shipping companies. Such idea in this program is utilised by directly merging theoretical knowledge with professional practice on special prepared training vessel. The work present also comparison of the acquired knowledge verification results of training participants with the results of engine cadets from last semester of the UMG Faculty of Engineering. The comparison includes computer exercises of Marine equipment and machineries (UNITEST Company – CBT) also genera ship and engine room knowledge checked by written test called “Final Test” carried out on the end of 3 months training.

Schlüsselwörter

  • ship power plant
  • watch engineer training
  • marine engineer competences
Uneingeschränkter Zugang

Are We Ready for Electric Cars?

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 69 - 74

Zusammenfassung

Abstract

Cars with electric drive are becoming more fashionable. More and more of them appear on the roads, especially in the centres of big cities. However, electric cars must be charged, preferably from high-power energy sources. In domestic environment, (if somebody owns a house) power available is usually of 10-16 kW. Users have to increase the level of household power or charge the car for several hours, because car charger is not the only home energy receiver. Some of the users are installing energy storage systems solution based on energy storage systems but this require additional expenses for batteries, inverter, circuit breakers and additional equipment. Other disadvantages of such solution are that they are mostly dedicated for stand-alone houses. What could be done by electric cars owners who live on the 10th floor in a block of flats? What would happen if everyone in the same time decided to buy an electric car? What will happen if everyone at the same time charges his or her cars? Do we have an adequate supply of energy potential? On the other hand, do we need to build new energy power plants? Will the electric grid cope with such a load or will have to build new transmission lines, transformer stations, and charging stations?

Schlüsselwörter

  • electric car
  • car battery charger
  • power supply
  • electricity production
Uneingeschränkter Zugang

Rotating Shaft Fault Prediction Using Convolutional Neural Network: A Preliminary Study

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 75 - 81

Zusammenfassung

Abstract

One of the most important subsystems of the vehicles and machines operating currently in industry and transportation are the rotating subsystems. During the operation, due to the forcing factors influence, the technical state of them is changing and the failure can occur. Fault diagnosis is maintenance task considered as an essential in such subsystems, since possibility of an early detection and diagnosis of the faulty condition can save both time and money. To do this the analysis of the subsystems vibrations is performed. The identified technical state should be considered in a context of the ability and different inability states. Therefore, the first step of the diagnostic procedure is the ability and different inability states identification.

Traditional data-driven techniques of fault diagnosis require signal processing for feature extraction, as they are unable to work with raw signal data, consequently leading to need for both expert knowledge and human work. The emergence of deep learning architectures in condition-based maintenance promises to ensure high performance fault diagnosis while lowering necessity for expert knowledge and human work. This article presents authors initial research in deep learning-based data-driven fault diagnosis of rotating subsystems. The proposed technique input raw three-axis accelerometer signal as high-definition image into deep learning layers, which automatically extract signal features, enabling high classification accuracy.

Schlüsselwörter

  • condition-based maintenance
  • rotating systems
  • fault diagnosis
  • convolutional neural networks
Uneingeschränkter Zugang

Main Aspects of a Maritime E-Navigation Project

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 83 - 90

Zusammenfassung

Abstract

Many devices and systems, including electronic ones, are used in the operation of sea-going vessels. Fast technological development in the field of electronics, radio communications and computer science inspires the more and more new proposals for the changes of these devices and systems. The rules and scope of sea-going vessels equipment, related to ensuring their safety, are strictly regulated by the International Maritime Organization (IMO). Considering the above, several countries have submitted to the IMO-Maritime Safety Committee (MSC) a proposal to prepare a vision of a broad strategy for incorporating new technologies in a structural manner, ensuring their compatibility with already existing different navigation and communication technologies and services. The overriding goal of this strategy would be to improve the efficiency, safety and reducing the cost of the entire system, providing global coverage and applicable to all types of sea-going vessels. In response to this proposal, the MSC decided to start work on the project “Preparation of e-navigation strategy”. The article presents the general concepts and goals of the e-navigation project. Priority needs of e-navigation users were also discussed. The key elements of the project are presented too. The radio communication aspects of the e-navigation project were also considered. Finally, the e-navigation Strategy Implementation Plan (SIP) and its progress were presented.

Schlüsselwörter

  • navigation
  • shipping
  • maritime e-navigation
  • maritime radio communication
  • ship safety
Uneingeschränkter Zugang

Quasi-Homogenous Model of Electrochemical Machining of Turbine Engine Parts

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 91 - 104

Zusammenfassung

Abstract

In order to increase the efficiency of jet engines hard to machine nickel-based and titanium-based alloys are in common use for aero engine components such as blades and blade integrated disks (BLISK). Electrochemical Machining (ECM) provides an economical and effective method for machining high strength and heat-resistant materials into complex shapes with high material removal rate without tool wear and without inducing residual stress. This article presents the physical and mathematical models of electrochemical shaping used in the manufacture of turbine engine parts. The modelling is based on the assumption that the multi-phase mixture filling the gap is treated as two-phase quasi-homogenous medium. The model describes the workpiece shape evolution in time, distribution the local gap size, flow parameters such as the static pressure and the velocity, temperature and void fraction as result of gas generation. The major features of the numerical computer program are briefly described with a selected example of machining a typical turbine blade. The results of computer simulation of effects of setting parameters ECM on accuracy-machined profile are discussed. The improvement of accuracy has been reached by using described sequence of ECM and Pulse ECM processes.

Schlüsselwörter

  • electrochemical shaping
  • modelling
  • simulation
  • pulse current
Uneingeschränkter Zugang

Research into the Effects of the Effective Microorganisms Addition on the Engine Oil Viscosity

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 105 - 112

Zusammenfassung

Abstract

In the article, changes in the properties of oils during operation were characterized. The main reason for this is the continuous aging process of the used oil caused by the interaction of oxygen contained in the air, which reacts relatively easily with hydrocarbons and the oxidation process is accelerated just by high temperature. Then the problem of microorganisms occurring in petroleum products and their effect on the properties of oils and the operation of the internal combustion engine was presented. The next part of the article presents effective microorganisms, i.e. what they are and how they work, in particular, their composition and appropriate development conditions. In addition, some of their specific applications were briefly described. In the next part of the article, the research methodology, applied oil samples with additives of effective microorganisms, both for fresh oil and used oil were described. In addition, the measuring test stand with instrumentation and measuring device was shown. The main part of the article contains the characteristics of dynamic viscosity as a function of temperature for fresh oil and used oil compared with oils with the addition of microorganisms in liquid form and ceramic tubes. The developed graphs enabled analysis of the effect of the addition of microorganisms on oil viscosity as ecological products.

Schlüsselwörter

  • petroleum products
  • oil viscosity
  • engine oil
  • microbiological contamination
  • effective microorganisms
Uneingeschränkter Zugang

Wind Tunnel Tests of the Tu-154M Aircraft Aerodynamic Characteristics

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 113 - 120

Zusammenfassung

Abstract

Determination of possible manoeuvres to be performed by the aircraft requires knowledge of its aerodynamic characteristics including, in particular, characteristics of the aircraft at configuration with deflected control surfaces. In this article, the wind tunnel tests results of the model of passenger Tu-154M aircraft manufactured at the scale 1:40 are presented. The model was designed and manufactured by the Military University of Technology based on the Tu-154M aircraft geometry obtained by full-scale object scanning. The model mapped all aircraft control surfaces, along with the gaps between these surfaces and the main wing part.

During the tests all the model’s control surface like, flaps, ailerons, spoilers, slots, rudder, elevator and tail plane were deflected at the same deflection angles range as they are used in the full scale aircraft. The aerodynamic characteristics of the tested Tu-154M aircraft model were measured by the 6-component internal balance. Based on the obtained measurements the aircraft model aerodynamic coefficients were calculated. In the article the basic aerodynamic characteristics of the tested Tu-154M aircraft model i.e. lift, drag coefficients as well as pitching, yawing and rolling moment coefficients versus model angles of attack and sideslip angles were presented.

The tests were performed in the Institute of Aviation low speed wind tunnels T-1 of the 1.5 m diameter test section at the undisturbed velocity, V∞ = 40 m/s.

Schlüsselwörter

  • applied aerodynamics
  • tests reliability
  • aerodynamic measurements
Uneingeschränkter Zugang

Models of the Reference Departure and Arrival IFR Procedures for the Purpose of Research in RPAS Integration in Controlled Airspace

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 121 - 128

Zusammenfassung

Abstract

The air operations in controlled airspace performed according to Instrument Flight Rules (IFR) are composed of three main flight phases, i.e. departure, cruise, arrival. Controlled airspace is divided into the terminal area and en-route airspace. The terminal area encloses the departure and arrival phases while the en-route airspace encloses the cruise phase. The IFR procedures are designed for manned aviation to ensure the safety of air operations. Development of the aviation concerns among others the increase in the number of unmanned aviation operations. Currently, on the European level, there is an on-going, long-term program of integration of the unmanned aviation in the uniform (non-segregated) airspace. This work concerns the research in the integration of the Remotely Piloted Aircraft Systems (RPAS) in the IFR procedures of the controlled airports. The objective was to build the reference models of Standard Instrument Departure and Arrival Procedures (SID and STAR). Basing on the procedure design guidelines the models of procedural nominal track, tolerance area, obstacle clearance area, climb or descend gradient, manoeuvres in SID and STAR were done. The guidelines describe the operational minima thus the statistics of existing procedures was done to select the suitable procedure parameters such as a number of navigational points, segments lengths, altitudes, climb or descent gradients. Reference models of SID include straight departure and turning departure procedures. Reference models of STAR include non-precision approach procedures according to used navigational aids, i.e. GNSS, VOR. The reference procedures were numerically implemented which will be used in the further works on RPAS integration problem by simulations of the RPAS ability to execute of the SID and STAR.

Schlüsselwörter

  • RPAS integration
  • SID and STAR
  • unmanned aviation
  • controlled airspace
  • controlled airports
Uneingeschränkter Zugang

The Full or Partial Replacement of Commercial Marine Engine Oil with Bio Oil, on the Example of Linseed Oil

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 129 - 135

Zusammenfassung

Abstract

The bio-oils are considered to sustainable, alternative and environmentally friendly source of lubricants compared to commercial engine oils, on the base a mineral, synthetic or semi-synthetic. They are obtained from natural raw material (vegetable or animal oils), which are renewable and non-toxic to humans, living organisms and environment. The vegetable oils called green oils, natural oils, bio-oils or natural esters. They can be obtained from plant seeds, that may be consumed – edible oils (for instance: rapeseed oil) or which cannot be consumed – inedible (for example: linseed oil).

The conducted research into linseed oil and its different quantity additives (25% and 50%) to commercial marine mineral oil intended for a medium-speed 4-stroke, trunk marine engine (i.e. Marinol RG 1240). The flash point and dependence of viscosity and temperature were compared and assess. It has been proven that vegetable oils have a high ignition temperature and very small viscosity change in the range of temperatures presented, i.e. high viscosity index.

According to the results, it can be recommended the addition of 25% linseed oil in the base lubricant is the relevant for lubricating a medium speed 4-stroke marine engine. The vegetable additives can improve a viscosity index a lube oil, and they will be positively affected environmental protection.

Schlüsselwörter

  • bio-lubricant
  • vegetable oil
  • linseed oil
  • engine oil
  • marine
  • mineral oil
  • inedible oil
  • viscosity
  • flash point
Uneingeschränkter Zugang

Characteristics of Carbon Dioxide and Product Water Exhausts in a Direct Methanol Fuel Cell with Serpentine Channels

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 137 - 144

Zusammenfassung

Abstract

This study utilized a transparent direct methanol fuel cell, with serpentine channels with a width of 2 mm and an initial depth of 2 mm, and investigated the relationship between the behaviours of carbon dioxide (CO2) slugs, product water accumulations, and voltage fluctuation. It examined the exhaust volumes of CO2 slugs and product water accumulations from the channels over time, comparing an anode channel with a depth of 1.2 mm to one with a depth of 2 mm (without changing the cathode depth of 2 mm, nor the width of 2 mm in both the anode and the cathode). Results indicated that cell voltage fluctuated, rising while CO2 slugs were ejected, and falling between ejections. In the case of an anode channel depth of 2 mm and a lower methanol-water solution flow rate, CO2 slugs were ejected less frequently, so cell voltage fluctuated widely. (Product water accumulations in the cathode had a minimum effect on this cell voltage fluctuation.) In the case of a higher methanol-water solution flow rate, CO2 slugs were ejected more frequently, with less exhaust volume per CO2 slug, reducing the fluctuation in cell voltage. Finally, with an anode channel depth of 1.2 mm, the exhaust volume per CO2 slug became even smaller, and these small CO2 slugs were rapidly ejected. With this shallow depth, the cell voltage increased with a lower methanol-water solution flow rate, but decreased with a higher methanol-water solution flow rate by crossover.

Schlüsselwörter

  • direct methanol fuel cell
  • bubble of carbon dioxide
  • slug of carbon dioxide
  • product water
  • transparent cell
  • serpentine channel
Uneingeschränkter Zugang

Planning the Flight Trajectory of a Passenger Aircraft with Regards to the Aspect of Pollutants Emission

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 145 - 153

Zusammenfassung

Abstract

One of the ways to reduce the adverse impact of aircraft on the environment is through the determination of the trajectory of the flight on a given route that leads to reducing fuel consumption and, consequently, emission of pollutants in jet engines exhausts. Planning a flight in terms of minimizing emissions or fuel consumption is a complex task and difficult to implement due to the conditions in which the aircraft travels, but it is possible though. It is necessary to take into account the limitations resulting from the organization of the airspace and the rules therein, as well as the current weather conditions. The weather is one of the main factors determining the amount of fuel consumed, the time and cost of a particular flight on a given route. In addition to the main parameters, such as pressure and air density, it is extremely important to determine the air temperature, as well as the wind speed and direction. The temperature affects the speed of sound, based on which it is possible to determine the Mach number for a plane flying with a given true air speed (TAS). The speed and direction of wind, on the other hand, affect the speed of the aircraft relative to the ground (velocity over ground, VOG), and thus the duration of its flight. The article describes how the developed model of emission of pollutants in the exhausts of jet bypass engines can be useful for determining the trajectory of an aircraft in its cruise phase due to the criterion of pollutants emissions minimization. An exemplary analysis was carried out for selected aircraft moving along the route adopted for the research. The analysis covered various cruising altitudes and various meteorological conditions (wind speed and direction). The obtained results are illustrated graphically and discussed.

Schlüsselwörter

  • aircraft
  • emission
  • cruise phase
  • flight trajectory
Uneingeschränkter Zugang

Determination of CO2 Emissions for Selected Flight Parameters of a Business Jet Aircraft

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 155 - 163

Zusammenfassung

Abstract

In the last two decades, there has been observed a noticeable increase in the popularity and availability of air transport services, including regional ones. This intensive development of transport is accompanied by an increase in the adverse impact to the environment, increases noise level, and exhausts emissions, despite the modification and modernization of engines. Determining the emission for regional flights takes into account the specificity of the aircrafts design, such as the size of the aircraft and the performance of the engines. In this article, an attempt was made to determine the CO2 emissions of a business jet flying from Gdansk to Rzeszow. The methodology of the research (the method of calculating emissions based on fuel consumption) and the performance characteristics of the aircraft engines have been described. In the first part of the article, the speed-altitude characteristics of the DGEN-380 engine for different cruise parameters were determined using the virtual engine test bench WESTT CS/B. These characteristics have enabled the engine to match the flight characteristics (altitude, speed). For specific flight parameters, the thrust and fuel consumption were determined. On this basis, for the adopted trajectory and flight time of an aircraft equipped with two DGEN-380 engines, total fuel consumption and CO2 emission factors and values in CRUISE phase was determined with regard to the wind speed and direction. The obtained results were illustrated graphically and discussed.

Schlüsselwörter

  • CO emissions
  • jet engines
  • business jet aircraft
Uneingeschränkter Zugang

Turbulent Triggers and the Model Quality Influence on Aerodynamic Characteristics of the Laminar Aerofoil in Transonic Flow Regime

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 165 - 172

Zusammenfassung

Abstract

The test with a roughness application on the laminar aerofoil has been conducted in the N-3 trisonic wind tunnel of the Institute of Aviation in Warsaw. The main goal of tests was to investigate the influence of the boundary layer transition triggers on a laminar profile aerodynamic characteristic. For baseline configuration, the natural transition was applied. As a local roughness on the upper model surface, the carborundum strips with different heights were applied. These were positioned on the upper model surface in the front of the shock position occurrence. The Mach number during test was equal Ma = 0.7 and Reynolds number was about 2.85·106. Tests have been conducted for different model incidence in range 0°-7°. Current article refers partially to the previous study, where aerofoil model with lower quality of surface had been tested. Investigation results from previous work indicated that some of transition positions improved an aerodynamic characteristic by reducing the drag coefficient value and decreasing shock wave unsteadiness in the transonic regime. However, current article indicates that beneficial effects in respect to the baseline configuration are also strictly dependent on the model quality and turbulent triggers size. Improved surface quality of the laminar aerofoil model affected on aerodynamic characteristics with and without turbulent triggers. Resultant aerodynamic coefficients of all tested cases i.e. drag, lift and lift to drag ratio were compared.

Schlüsselwörter

  • transonic flow
  • aerofoil
  • model quality
  • aerodynamic characteristics
  • shock wave
Uneingeschränkter Zugang

Analysis of Ratios of Propulsion Energy Demand for Transport by Bulk Carriers

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 173 - 180

Zusammenfassung

Abstract

The article presents the results of calculations and analysis of the eM ratio of the propulsion energy consumption per the nautical mile and the eMt ratio of the propulsion energy demand for the transport of 1-ton cargo per the nautical mile for bulk carriers. The relationship between eM and eMt indicators with the EIV (Estimated Index Value) ratio is shown. The output data for the determination of eM and eMt indicators was taken from the quoted MAN publication, reading (reproducing) the values of power, velocity v and DWT tonnage from the charts included in this publication. Calculations and analyses were made for velocity v between 11-15 knots and for DWT from 5-400 kt (kilo tonnes). The graphs of eM and eMt ratios in the function of speed v and load capacity DWT are presented. Using the stepwise method of least squares, models of statistical dependence of indicators on velocity v and load capacity of bulk carriers were developed. They were based on generalized polynomials with integer exponents. Derivatives deM / dv and deMt / dv and derivatives deM / dDWT and deMt / dDWT were determined. The main observations resulting from the conducted analyses are observed with the increase of DWT (within the range of 80-100 kt) a significant decrease in the value of the eM index. For DWT values> 100 kt, the decrease in eMt is slow − eMt asymptotically tends to a constant value. The results of the analyses carried out can be used at the stage of designing the transport capacity (tonnage) and nominal speed of the ship as well as selection of ship tonnage and travel speed in a given transport situation.

Schlüsselwörter

  • bulk carriers
  • transport
  • ratio of energy consumption per Nautical Mile
  • ratio of energy consumption per Nautical Mail and per one ton of DWT
Uneingeschränkter Zugang

Influence of Heat Treatment on Corrosion Properties of Non-Alloy Steel in Acidic Environment

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 181 - 188

Zusammenfassung

Abstract

The article presents the influence of heat treatment on corrosion properties of non-alloy steel. This steel is used in machine elements. Heat treatment has a major impact on corrosion resistance of steel materials. Laboratory methods for measuring the corrosion rate consist of Electrochemical Impedance Spectroscopy and polarization curves. Instead of these types, there are also industrial methods of velocity corrosion measurements like researches in natural conditions and coupons corrosimetry. These days the most popular techniques of corrosion measurements are electrochemical measurements. In order to conduct impact assessments influent of heat treatment to corrosion properties there is need to proceed few steps like prepare samples, carry out heat treatment, hardness measurements, metallographical examination, prepare samples for corrosion and proceed corrosion researches by potentiodynamic method. An important element during researches is corrosion allowance, which has an impact influent on corrosion properties. This is the most popular and efficient method of corrosion protection. These days for corrosion protection are use paints or zinc coatings, cathode protection or stainless.

Schlüsselwörter

  • corrosion process
  • non-alloy steel
  • corrosion preventive coatings
  • heat treatment
  • corrosion allowance
Uneingeschränkter Zugang

Problems of an Aerodynamic Interference between Helicopter Rotor Slipstream and an Elevated Heliport

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 189 - 196

Zusammenfassung

Abstract

An elevated heliport, as it has been defined by FAA (Federal Aviation Administration), is a heliport located on a rooftop or other elevated structure where the TLOF (touchdown and lift-off area) is at least 30 inches (76 cm) above the surrounding surface [1]. One of greatest advantages of such heliports is that they require less free space, which eases its build nearby existing buildings – especially in densely built-up areas. However, design of such heliports is more complicated, than ground level ones, while one must include an aerodynamic impact of the building below the elevated heliport and surrounding buildings. The aerodynamic interference between the helicopter and the buildings may result with decline of flight safety, due to sudden decrease of thrust (when flying above the edge of building) or because of increased turbulence in windy weather, wake behind surrounding buildings causing sudden gusts etc. Moreover, oscillations of pressure caused by helicopter rotor influence on the building structure also must be taken into account due to increased wear of upper part of the building or devices mounted on its roof (for example, elevator drives). These oscillation may also cause vibrations of building’s structure, which is especially important in case of medical heliports – which are a vast majority of elevated heliports (and heliports in general) – because of strict requirements for acceptable vibration level. The article is aimed on summarize aerodynamic issues, which should be taken into account during design of elevated heliport.

Schlüsselwörter

  • transport
  • helicopter flight safety
  • rotor wake
  • elevated heliport
Uneingeschränkter Zugang

Cooled Turbine Cantilevered Nozzle Mounting and Sealing System

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 197 - 202

Zusammenfassung

Abstract

Small advanced turboprop and turboshaft engines, with two-stage high-pressure turbine (HPT), need to meet several challenges. Described herein is an exemplary solution adopted for a cantilevered HPT nozzle mounting and sealing system that helped to meet requirements for size constraint and sealing of split lines and mounting features. Since clearances do not scale down with engine size due to manufacturing tolerances, there is a very limited space available between first and second stage rotors to secure HPT nozzle and to provide means of cooling air supply. Due to small diameters, cavities and size of the parts and assembly access becomes very difficult and precluded the use of typical solutions – like supply air spooilers – known from bigger engines. Relatively larger clearances require also efficient solution for sealing leakage, which was achieved by means of high-temperature braided “rope seals”. The nozzle segments have weight effective hook-type outer band mounting to HPT outer casing and are axially retained by HPT shroud with a snap ring. The hook cavities were used as pockets for rope seals that are subsequently compressed during assembly making it more difficult. However, by special design of the pockets and parts engagement sequence, the assembly process was optimized even though it is so called blind assembly. The sealing system function is not only reducing leakages that are detrimental to a turbine efficiency, but also allow for pressurizing the cavity between the nozzle outer band and HPT outer casing with cooling air thus preventing from hot gas ingestion by higher back-flow margin (BFM) resulting in higher durability of the turbine.

Schlüsselwörter

  • transport
  • gas turbine
  • cooled turbine
  • cantilevered nozzle segment
  • sealing
Uneingeschränkter Zugang

Particulate Matter Emission Reduction from Marine Diesel Engines by Electrohydrodynamic Methods

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 203 - 210

Zusammenfassung

Abstract

Particulate matter (PM) and gaseous compounds (SO2, NOx, VOC) emitted by diesel engines causes serious global environmental problems and health impact. Despite numerous evidences about the harmfulness of diesel particles, the PM emission by diesel engines used by ships, cars, agricultural machines, or power generators is still unregulated, and the efficient removal of PM from diesel exhausts is still the major technological challenge. In order to comply with the International Maritime Organization regulation, the NOx emission is reduced by using selected catalytic reactor, and sulphur oxide emission has been reduced by using fuels of low sulphur content. However, both of those measures cannot be used for the reduction of PM emission produced during combustion of marine fuels. The lack of appropriate regulations results from insufficiently developed technology, which could remove those particles from exhaust gases. Conventional scrubbers currently available on the market remove only sulphur oxide with required collection efficiency, but the collection efficiency for PM2.5 is below 50%. The article discusses the technical means used for the removal of PM from marine diesel engines via applying electrohydrodynamic methods, in particular electrostatic agglomeration, as a method of nanoparticles coagulation to larger agglomerates, which could operate in two-stage electrostatic precipitation systems, and electrostatic scrubbers, which remove particles by electrically charged water droplets. The experimental results were obtained for a 2-stroke 73 kW diesel engine fuelled with marine gas oil (MGO). The agglomerator allowed increasing the collection efficiency from diesel exhausts for PM2.5 particles by about 12%, compared to electrostatic precipitator operating without agglomerator, and the total mass collection efficiency was above 74%. The collection efficiency of electrostatic scrubber was higher than 95wt.%. The advantage of using the electrostatic scrubber is that it can also reduce the SO2 emission by more than 90%, when HFO is used.

Schlüsselwörter

  • exhaust gases
  • marine diesel engines
  • particulate matter (PM)
  • scrubber
Uneingeschränkter Zugang

Helicopter Flight Simulation based on URANS Solver and Virtual Blade Model

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 211 - 217

Zusammenfassung

Abstract

The methodology of simulation of a rotorcraft flight has been developed and applied to simulate several stages of flight of light helicopter. The methodology is based on coupling of several computational models of Computational Fluid Dynamics, Flight Dynamic. The essence of the methodology consists in calculation of aerodynamic forces acting on the flying rotorcraft by solving during the simulation the Unsteady Reynolds-Averaged Navier-Stokes (URANS) equations. In this approach, the rotorcraft is flying inside the computational 3D mesh modelling the space filled with the air. The flight simulation procedure is completely embedded in the URANS solver ANSYS FLUENT. Flow effects caused by rotating blades of main or tail rotor are modelled by application of the developed Virtual Blade Model (VBM). In this approach, real rotors are replaced by volume discs influencing the flow field similarly as rotating blades. Time-averaged aerodynamic effects of rotating blades are modelled using momentum source terms placed inside the volume-disc zones. The momentum sources are evaluated based on the Blade Element Theory, which associates local flow parameters in the blade sections with databases of 2D-aerodynamic characteristics of these sections. Apart of the VBM module, two additional UDF modules support the simulation of helicopter flight: the module responsible for modelling of all kinematic aspects of the flight and the module gathering the momentary aerodynamic loads and solves 6 DOF-Equations describing a motion of the helicopter seen as solid body. Exemplary simulation of helicopter flight, starting from a hover, through an acceleration and fast flight until a deceleration and steep descent, has been discussed.

Schlüsselwörter

  • helicopter flight simulation
  • URANS
  • Virtual Blade Model
Uneingeschränkter Zugang

Influence of Seawater Salinity on Corrosion of Austenitic Steel

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 219 - 225

Zusammenfassung

Abstract

Due to the paramagnetic properties and the ability to passivation, for the production of hulls of some vessels (mainly warships), corrosion-resistant (stainless) steels with austenitic structure are used. This article describes the influence of seawater salinity on selected corrosion properties of high-alloy steel X5CrNi 18-10 (304). The average salinity of the seas is taken as 3.5% content of sodium chloride. Corrosion rate of the tested material was evaluated in an aqueous solution of sodium chloride was evaluated. The NaCl concentration in corrosive solutions was 0.7%, 1.4%, 2.1%, 2.8%, 3.5%, 4.2%. Corrosion tests were performed using the potentiodynamic method. The range of electrochemical potential changes was Ecorr ±150 mV. Corrosion rate was assessed on the basis of corrosion current density measurements. Corrosion potential values against the saturated calomel electrode were also determined. Based on the obtained measurement results and non-parametric significance tests carried out, a significant influence of seawater salinity on the value of corrosion current density and corrosion potential was found. The highest value of corrosion current density (jcorr), and thus the highest corrosion rate, was recorded for 3.5% NaCl solution. In the concentration range from 0.7 to 3.5% NaCl in solution, the corrosion rate of austenitic steel increases. A further increase in salinity of electrolyte results in the inhibition of corrosion rate of steel. There is almost a full negative, linear correlation between the proportion of sodium chloride in the corrosive solution and the value of corrosion potential. Along with the rise in the salinity of seawater, increase the electrochemical activity, and thus the corrosion susceptibility, thus the corrosion susceptibility, of the austenitic steel X5CrNi 18-10 was observed.

Schlüsselwörter

  • austenitic steel
  • corrosion
  • potetiodynamic test
  • seawater
Uneingeschränkter Zugang

Reducing Emission of Harmful Toxic Substances by Trucks in the Aspect of Analysis of Selected Vehicle Operating Parameters and Human Factor

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 227 - 234

Zusammenfassung

Abstract

Digital tachographs as devices recording the work of a lorry and driver’s work are a constant factor in the work of a professional driver. It is therefore important to preserve the security of recording and storing electronic information. In this matter, cryptography also becomes an inseparable field of science. The control services set up to conduct roadside inspections do not detect all violations in the recording devices by encrypting information in information systems. One of the frequent vehicle operating parameters that can be falsified are the speed of the vehicle and its rotational speed, as well as the time and efficiency of the driver’s work. These parameters affect the amount of fuel consumption. The reduction of fuel consumption translates directly to the reduction of harmful substances emitted by the car to the environment. Variable compression engines are becoming the future of motoring in the case of internal combustion engines. It is noticeable that there are more frequent deliberate of regulations; and more violations rules concerning the proper functioning of recording devices by recording driver activity. Current methods of preventing violations are insufficient. The article points out the violations related to the actual rotational speed of the crankshaft of the internal combustion engine in relation to the vehicle speed profile, which is directly related to the fuel consumption and the emission of harmful substances. The article describes the ways to reduce fuel consumption, of which the correct driving technique is important in addition to the previously marked parameters. The factors that increase the awareness of professional drivers in the aspect of proper driving techniques are described.

Schlüsselwörter

  • eco-driving training
  • rotation speed
  • digital tachograph system
  • recording equipment
  • road transport
Uneingeschränkter Zugang

Strength Analysis of Polymer Conical Gear Wheel Made with 3D Printing Technique

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 235 - 242

Zusammenfassung

Abstract

The article deals with the problem of designing conical gears with a curved line contour. The contour of the tooth flank is described by means of a helix and involutions. In the work, a conical gear designed to drive of the lower limb rehabilitation exoskeleton has analysed. Parameters of the conical gearbox have been adapted to design requirements of the exoskeleton. Gear wheels were made with ABS material using 3D printing technique. The article presents the results of strength calculations obtained using the method classical design of the gear wheals described in the norm ISO 6336-1996. In the strength calculations, bending and contact stresses were taken into account. Creating the contour of gears was aided through the gearbox wizard available in Inventor program. The work contains the results of a static tensile test of the material from which the gear wheels were made. In experimental and numerical studies, the orthotropy of the material used was taken into account. The orthogonal values of the Young’s modulus, the Poisson’s ratio and the Kirchhoff’s modulus were determined. The publication also includes partial results of fatigue tests in the area of normal stresses. In the research used to finite element method (FEM), determine of internal loads in the gear. A structure of the FEM model is described in detail. Maximum values of contact pressures determined by use to FEM models have been compared with the results obtained on the basis of Hertz’s formulas. The article presents basic geometrical and strength parameters of the designed gear. The work demonstrates the validity of the material models used. Limitations in the application of the classic method of calculating conical gears made of orthotropic materials have been indicated. The results of analytical and numerical calculations are presented in tabular and graphical form.

Schlüsselwörter

  • Exoskeleton
  • strength analysis
  • finite element method (FEM)
  • material model of acrylonitrile-co-butadiene-co-styrene
  • conical gears
Uneingeschränkter Zugang

The Process of Regenerative Heat Treatment of the Valve Chamber of the Steam Turbine

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 243 - 248

Zusammenfassung

Abstract

Steel castings are often used in the construction of valve chambers of steam turbines. Stringent requirements are set due to the continuous operation of the material at elevated temperatures, in the order of 300°C to 600°C. The material of the valve chamber must be resistant to fatigue-creep changes as well as corrosion. This material must be also resistant to dynamic damage which occures when the turbine is starting and stopping. Dynamic damage is induced by a short-lasting but intense accumulation of localized stresses. The castings of the valve chambers of the steam turbine are usually made from the “three-component” type CrMoV-cast steel. Mentioned castings of the valve chamber are continuously subjected to high temperatures, either constant and periodically variable stresses. Due to this, the degradation process of material of the castings is taking place. It is caused by physicochemical processes such as: creep, relaxation, thermal fatigue, corrosion, erosion and changes in material properties, e.g. displacement of the critical point of brittleness. Finally, first cracks and deformations can be observed in the material during the operation. The art presents the process of revitalization technology of the steam turbine valve chamber which was subjected to long-term operation at high temperatures. The revitalization process is aimed at improving the plastic properties of the material and, as the result, extending its service life. The research presented in the article show that impact strength of the chamber material after revitalization is very high. Also the strength properties of the valve chamber, after revitalization, are high and in line with the requirements. The study show that the revitalization of the valve chamber was carried out correctly and restored the material to plastic deformation.

Schlüsselwörter

  • regenerative heat treatment
  • valve chamber
  • steam turbine
Uneingeschränkter Zugang

Research the Possibility of Obtaining Diagnostic Information about the Ships Engine Fuel Injection System Condition based on the Analysis of Characteristics of Heat Release

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 249 - 256

Zusammenfassung

Abstract

Marine engines are very complex technical objects, having many important functional systems, which include, inter alia, injection system, characterized by high unreliability. In this system, there may be different types of defects (damage) that affect the engine parameters, including specific fuel consumption, as well as failures endanger the safety of the ship. The indicator diagrams and analysis of indicated parameters have limited utility in the diagnosis of damages of marine engine, although this is a method commonly used in operational practice. To achieve greater diagnostic effectiveness, when, based on indicator diagrams, are calculated and then the characteristics of heat release is analysed - net of heat release characteristics and the intensity of the heat release, it was demonstrated. This procedure is particularly effective in the diagnosis of damages of marine diesel engine injection system components. It has been shown that the characteristics of heat release contain information about the condition of the injection systems, which enable to diagnose their failures. This is shown on the example of a clogged nozzle holes (their carbonizations). The obtained results allowed selecting the diagnosis symptoms, useful in detecting these faults in the injection system, from the characteristics of heat release: net heat release (Q) and intensity of heat release (q). The object of the research was typical marine medium speed engine Sulzer A25/30.

Schlüsselwörter

  • marine diesel engine
  • indicated parameters
  • indicator diagram
  • heat release characteristics
  • injection system
  • diagnostic
Uneingeschränkter Zugang

A Prototype Test Stand for Testing Insolated Rotor Systems

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 257 - 264

Zusammenfassung

Abstract

The article discusses assumptions for a prototype test stand designed for testing rotors in the conditions of work at their nominal speed, in particular gyrocopter and helicopter rotors. In the work presents an overview of similar solutions of test stand presented in the available literature and solutions proposed by companies, such as Swangate International or Luftfahrttechnik GmbH. Beyond these solutions the article also contains test stand used so far at the Institute of Aviation, these solutions were prepared for testing one type of rotor (for example: only for gyroplane rotors). The article provides the steps of designing a new test stand, which one of the basic assumptions is that it will be a universal test stand, giving the possibility to test different types of rotors. The article discusses two concepts of the stand with electric engine as a drive, gives the advantages and disadvantages of each concept, and indicates the selected solution. In addition to design and applied drive solution of the stand, the measuring part and data acquisition were also discussed. Moreover, the article focus on the advantages of rotor testing using the presented solution, as well as problems encountered during tests, in particular related to construction free vibrations and resonance. Vibration and resonance of the test stand are very important aspect of the entire design process, because it affects the quality and safety of the tests.

Schlüsselwörter

  • test stand
  • main rotor
  • design
  • construction resonance
Uneingeschränkter Zugang

Gyroplane Rotor Hubs Strength Tests

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 265 - 270

Zusammenfassung

Abstract

In this article a review of rotor, hub constructions were presented. Discussed rotor’s hub is made of composite or aluminum alloys materials. Two types of rotor hub were presented (four-blades and two-blades teetering rotor hub), each of them are dedicated to gyroplanes. Typical gyroplane main rotors are characterized by simple design, especially in case of rotors for light gyroplanes. In the following part of the article the type of strength tests required by certification process were shown. The test programs based on legal aspects of admission to the flight tests taking into account legislation such as CS 27 (Subpart C – Strength Requirements), CAP 643 British Civil Airworthiness requirements Section T Light gyroplanes, ASTM F2972. Furthermore, this article discusses strength tests of gyroplane rotor hub such as measured parameters, methodology of measurement, types of sensors, course of test, test stands, and limit loads. The loads during “pull-up from level flight” manoeuvre are limit loads during tests. Required additional processes, like a verification the same parameters by two types of method were shown i.e. deformation of structure were tested by strain gauges and reverse engineering. Strength tests had to be made before flight test, based on results of them aircrafts are flight authorized. In conclusion, the results of tests were presented and fulfilment of legal assumptions and requirements were shown.

Schlüsselwörter

  • gyroplane
  • strength tests
  • rotor hub
  • aviation regulations
33 Artikel
Uneingeschränkter Zugang

Comparison of Reduction Systems of Harmful Substances into the Atmosphere in Accordance to Requirements of IMO Tier III

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 7 - 14

Zusammenfassung

Abstract

Degradation of the environment is nowadays believed to be the most alarming problem that needs to be solved. Global warming and environmental pollution are predicted to cause a catastrophic chain reaction leading to species extinction, mass emigration due to rising sea levels and global crisis. The only solution suggested by international organizations is the immediate reduction of greenhouse gases and other harmful substances. Marine transportation harmful substances into the atmosphere are recognized to be a significant source of global atmospheric pollution. Despite the high efficiency of marine diesel engines, their impact on the environment is considerable. Due to environmentally friendly policies, modern engines concerns about not only efficiency but also mainly about s aspects. This article analyses and compares marine s exhaust gases reduction methods. Especially the most harmful substances emitted by ships were taken into consideration. The article presents the most crucial law regulations of harmful substances to the atmosphere, pointing at actual and possible future implementations. The most complex methods allowing meeting the latest limits were presented. Pros and cons of available control methods were thoroughly described and methods were compared. The most adequate methods form the effectiveness and economical point of view was pointed out.

Schlüsselwörter

  • NOx
  • SOx
  • MARPOL
  • atmosphere pollution
  • marine transportation
  • dual fuel
Uneingeschränkter Zugang

The Application of the BSSD Iono-Free Linear Combination Method in the Processing of Aircraft Positioning

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 15 - 21

Zusammenfassung

Abstract

The article presents the results of research into the use of the differentiation technique of BSSD (Between Satellite Single Difference) observations for the Iono-Free LC combination (Linear Combination) in the GPS system for the needs of aircraft positioning. Within the conducted investigations, a positioning algorithm for the BSSD Iono-Free LC positioning method was presented. In addition, an experimental test was conducted, in which raw observational data and GPS navigation data were exploited in order to recover the aircraft position. The examination was conducted for the Cessna 172 and the on-board dual-frequency receiver Topcon HiperPro. The experimental test presents the results of average errors of determining the position of the Cessna 172 in the XYZ geocentric frame and in the ellipsoidal BLh frame. Furthermore, the article presents the results of DOP (Dilution of Precision) coefficients, the test of the Chi square internal reliability test and the HPL and VPL confidence levels in GNSS precision approach (PA) in air transport. The calculations were performed in the original APS software (APS Aircraft Positioning Software) developed in the Department of Air Navigation of the Faculty of Aeronautics at the Polish Air Force University.

Schlüsselwörter

  • GPS system
  • aircraft positioning
  • BSSD Iono-Free linear combination
  • air navigation
Uneingeschränkter Zugang

The Physical Modelling of High Speed Broaching of the Heat-Resistant Steels for Studies Surface Layer Quality

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 23 - 29

Zusammenfassung

Abstract

The main idea of the work is to create a physical model of high speed broaching heat-resistant materials is used to study the parameters of the surface layer quality. Modelling is a method of mediated cognition, in which the object under study is in some correspondence with the model, and the object-model is capable in some way or another to replace the original at some stages of the cognitive process. Physical modelling is primarily distinguished by the fact that studies are conducted on models with physical similarity, i.e. preserving completely (or at least partially) the nature of the phenomena. The work of the broach can be likened to the work of a number of planning cutter displaced relative to each other by a small amount, which is called lifting (feed per tooth). Therefore, for experimental work, a planning cutter of a special geometric was designed and manufactured – a physical model of a broach, in which geometric, mechanical and dynamic similarity is realized. The article also presents an experimental justification for the use of the created physical model in the study of the surface quality parameters of the, tab grooves of turbine and compressors disks made of heat-resistant materials.

Schlüsselwörter

  • physical modelling
  • high-speed broaching
  • surface quality
  • tab grooves
  • heat-resistant steel
Uneingeschränkter Zugang

An Attempt to Reduce the Emission of Spark-Ignition Engine with Mixtures of Bioethanol and Gasoline as Substitute Fuels

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 31 - 38

Zusammenfassung

Abstract

Limiting emissions of harmful substances is a key task for vehicle manufacturers. Excessive emissions have a negative impact not only on the environment, but also on human life. A significant problem is the emission of nitrogen oxides as well as solid particles, in particular those up to a diameter of 2.5 microns. Carbon dioxide emissions are also a problem. Therefore, work is underway on the use of alternative fuels to power the vehicle engines. The importance of alternative fuels applies to spark ignition engines.

The authors of the article have done simulation tests of the Renault K4M 1.6 16v traction engine for emissions for fuels with a volumetric concentration of bioethanol from 10 to 85 percent. The analysis was carried out for mixtures as substitute fuels – without doing any structural changes in the engine's crankshafts. Emission of carbon monoxide, carbon dioxide, hydrocarbons, oxygen at full throttle for selected rotational speeds as well as selected engine performance parameters such as maximum power, torque, hourly and unit fuel consumption were determined.

On the basis of the simulation tests performed, the reasonableness of using the tested alternative fuels was determined on the example of the drive unit without affecting its constructions, in terms of e.g. issue. Maximum power, torque, and fuel consumption have also been examined and compared. Thus, the impact of alternative fuels will be determined not only in terms of emissions, but also in terms of impact on the parameters of the power unit.

Schlüsselwörter

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

Investigation of the Effect of Diamond Powder on the Thermal Properties of Octadecane Using Differential Scanning Calorimetry

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 39 - 45

Zusammenfassung

Abstract

The purpose of this work was to examine the effect of diamond powder on the thermal properties of phase change materials on the example of octadecane. The experiment involved mixing of diamond powder with a specific granulation with the aforementioned representative of the alkanes group. Two different grain sizes were used: 50 and 250 micrometres. The change of specific heat, latent heat of phase change and degree of supercoiling in newly formed mixtures was compared to the pure forms of the phase-change materials used. Initial mixing with a glass-stirring rod showed strong stratification for each granulation due to the low viscosity of the mixture and too large differences between component densities. It was decided to add amorphous silicon dioxide to the mixtures, which increases density of the mixture. The optimal percentage of amorphous silicon dioxide was estimated experimentally. Measurements of thermal parameters were carried out using DSC technology. The results of the tests of specific heat and latent phase transition heat showed that with the increasing content of diamond, the specific heat of the mixture decreases almost twice, and the latent heat can decrease by up to three times. The effect of diamond powder on reducing the degree of supercoiling of the mixture was also observed. An important observation was that the mixture with higher granulation of diamond powder had greater tendency for sedimentation. This method could be used to increase thermal conductivity and diffusivity of phase change materials and make them viable for use in systems that require cooling at high rate or temperature stabilization, such as control systems in electronic vehicles or aviation industry and at the same time decrease the degree of supercoiling which could increase the efficiency of system.

Schlüsselwörter

  • phase change materials
  • PCM
  • diamond powder
  • thermal conductivity
  • thermal diffusivity
Uneingeschränkter Zugang

Results from Laboratory Tests of New Electric Brake Prototype

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 47 - 52

Zusammenfassung

Abstract

The main idea of this article was to compare the results of new design electric brake to the older version of hydraulic brake in laboratory tests. The energy of braking should be very similar due to the same mass of the airplane. That is why the laboratory tests of both brakes were took place in the same stand. Of course, the parameters were similar but not at all. The main idea was to create the solution, which could be used in vehicle like airplane. The electric brakes could replace traditional hydraulic brake solution. The results could be interesting for every researcher who is interested in brakes. Other important idea of this article was to describe the tests of new electric brake prototype. The purpose of the tests was to check designing of electric brakes. The electric brake prototype should ensure sufficient efficiency, safety, reliability and durability during braking, which is required in certification processes and is particularly important when researching innovative solutions. It was really important to verify the design and check the parameters. Of course, there is really important to remember that in every new type of the prototype solutions there are many pros and cons, which are typical only for considered design. Nowadays every electric brake design is different because there is a lot of new concept.

Schlüsselwörter

  • laboratory test
  • electric brake
  • braking process
Uneingeschränkter Zugang

Overhead Travelling Crane Construction Deflection Measurements with Telematic Approach

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 53 - 60

Zusammenfassung

Abstract

Transport has always been a fundamental impulse for the development of civilization. Issues related to the regularity of operation of technical systems, in the last decade have become important issues being considered from both the point of view, as well as economics. Today the major threat in the operational reliability constitutes intensification of the machine and equipment use leading to excessive degradation. In automated manufacturing processes where the material handling operations are realized by the cranes, the safety as both devices and operating people constitute important factor. The main purpose of the article was focused on the set of issues including the material handling devices (MHD) reliability shaping problem especially presents work in progress towards development the MHD condition assessment system with using telematic approach. In the article author, special care was enclosed to MHD devices with strength human factor interaction and relatively large construction, so the overhead travelling crane was chose. The object of the statement constitutes an attempt of collecting the knowledge concerning a possibility of use modern measurement systems to monitoring crane bridge deflection. All tests and considerations were conducted on the double girder overhead travelling crane with hosting capability 1000 kg and bridge span 8000 mm.

Schlüsselwörter

  • crane bridge deflection
  • total station
  • telematics
Uneingeschränkter Zugang

Engine Cadets with and Without Additional Training on Training Vessel – Competences Comparison Case Study

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 61 - 68

Zusammenfassung

Abstract

In the last decade evolution of the requirements for training and professional competences of ship’s crewmembers, including ship engineers can be observed. Despite the implementation of training programs according to IMO requirements in maritime training centres, a different level of competence of young people beginning their professional career on ships in the engine department is observed. The article discusses general conventions, goals, and effects of the “BS Cadet Program” training program, introduced by one of the larger German ship-owner to improve the competencies of crewmembers at the operational level, who will take duties of the watch engineer in the ship engine room soon. General idea of this training program is reducing the time of the path career what is a standard in most shipping companies. Such idea in this program is utilised by directly merging theoretical knowledge with professional practice on special prepared training vessel. The work present also comparison of the acquired knowledge verification results of training participants with the results of engine cadets from last semester of the UMG Faculty of Engineering. The comparison includes computer exercises of Marine equipment and machineries (UNITEST Company – CBT) also genera ship and engine room knowledge checked by written test called “Final Test” carried out on the end of 3 months training.

Schlüsselwörter

  • ship power plant
  • watch engineer training
  • marine engineer competences
Uneingeschränkter Zugang

Are We Ready for Electric Cars?

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 69 - 74

Zusammenfassung

Abstract

Cars with electric drive are becoming more fashionable. More and more of them appear on the roads, especially in the centres of big cities. However, electric cars must be charged, preferably from high-power energy sources. In domestic environment, (if somebody owns a house) power available is usually of 10-16 kW. Users have to increase the level of household power or charge the car for several hours, because car charger is not the only home energy receiver. Some of the users are installing energy storage systems solution based on energy storage systems but this require additional expenses for batteries, inverter, circuit breakers and additional equipment. Other disadvantages of such solution are that they are mostly dedicated for stand-alone houses. What could be done by electric cars owners who live on the 10th floor in a block of flats? What would happen if everyone in the same time decided to buy an electric car? What will happen if everyone at the same time charges his or her cars? Do we have an adequate supply of energy potential? On the other hand, do we need to build new energy power plants? Will the electric grid cope with such a load or will have to build new transmission lines, transformer stations, and charging stations?

Schlüsselwörter

  • electric car
  • car battery charger
  • power supply
  • electricity production
Uneingeschränkter Zugang

Rotating Shaft Fault Prediction Using Convolutional Neural Network: A Preliminary Study

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 75 - 81

Zusammenfassung

Abstract

One of the most important subsystems of the vehicles and machines operating currently in industry and transportation are the rotating subsystems. During the operation, due to the forcing factors influence, the technical state of them is changing and the failure can occur. Fault diagnosis is maintenance task considered as an essential in such subsystems, since possibility of an early detection and diagnosis of the faulty condition can save both time and money. To do this the analysis of the subsystems vibrations is performed. The identified technical state should be considered in a context of the ability and different inability states. Therefore, the first step of the diagnostic procedure is the ability and different inability states identification.

Traditional data-driven techniques of fault diagnosis require signal processing for feature extraction, as they are unable to work with raw signal data, consequently leading to need for both expert knowledge and human work. The emergence of deep learning architectures in condition-based maintenance promises to ensure high performance fault diagnosis while lowering necessity for expert knowledge and human work. This article presents authors initial research in deep learning-based data-driven fault diagnosis of rotating subsystems. The proposed technique input raw three-axis accelerometer signal as high-definition image into deep learning layers, which automatically extract signal features, enabling high classification accuracy.

Schlüsselwörter

  • condition-based maintenance
  • rotating systems
  • fault diagnosis
  • convolutional neural networks
Uneingeschränkter Zugang

Main Aspects of a Maritime E-Navigation Project

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 83 - 90

Zusammenfassung

Abstract

Many devices and systems, including electronic ones, are used in the operation of sea-going vessels. Fast technological development in the field of electronics, radio communications and computer science inspires the more and more new proposals for the changes of these devices and systems. The rules and scope of sea-going vessels equipment, related to ensuring their safety, are strictly regulated by the International Maritime Organization (IMO). Considering the above, several countries have submitted to the IMO-Maritime Safety Committee (MSC) a proposal to prepare a vision of a broad strategy for incorporating new technologies in a structural manner, ensuring their compatibility with already existing different navigation and communication technologies and services. The overriding goal of this strategy would be to improve the efficiency, safety and reducing the cost of the entire system, providing global coverage and applicable to all types of sea-going vessels. In response to this proposal, the MSC decided to start work on the project “Preparation of e-navigation strategy”. The article presents the general concepts and goals of the e-navigation project. Priority needs of e-navigation users were also discussed. The key elements of the project are presented too. The radio communication aspects of the e-navigation project were also considered. Finally, the e-navigation Strategy Implementation Plan (SIP) and its progress were presented.

Schlüsselwörter

  • navigation
  • shipping
  • maritime e-navigation
  • maritime radio communication
  • ship safety
Uneingeschränkter Zugang

Quasi-Homogenous Model of Electrochemical Machining of Turbine Engine Parts

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 91 - 104

Zusammenfassung

Abstract

In order to increase the efficiency of jet engines hard to machine nickel-based and titanium-based alloys are in common use for aero engine components such as blades and blade integrated disks (BLISK). Electrochemical Machining (ECM) provides an economical and effective method for machining high strength and heat-resistant materials into complex shapes with high material removal rate without tool wear and without inducing residual stress. This article presents the physical and mathematical models of electrochemical shaping used in the manufacture of turbine engine parts. The modelling is based on the assumption that the multi-phase mixture filling the gap is treated as two-phase quasi-homogenous medium. The model describes the workpiece shape evolution in time, distribution the local gap size, flow parameters such as the static pressure and the velocity, temperature and void fraction as result of gas generation. The major features of the numerical computer program are briefly described with a selected example of machining a typical turbine blade. The results of computer simulation of effects of setting parameters ECM on accuracy-machined profile are discussed. The improvement of accuracy has been reached by using described sequence of ECM and Pulse ECM processes.

Schlüsselwörter

  • electrochemical shaping
  • modelling
  • simulation
  • pulse current
Uneingeschränkter Zugang

Research into the Effects of the Effective Microorganisms Addition on the Engine Oil Viscosity

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 105 - 112

Zusammenfassung

Abstract

In the article, changes in the properties of oils during operation were characterized. The main reason for this is the continuous aging process of the used oil caused by the interaction of oxygen contained in the air, which reacts relatively easily with hydrocarbons and the oxidation process is accelerated just by high temperature. Then the problem of microorganisms occurring in petroleum products and their effect on the properties of oils and the operation of the internal combustion engine was presented. The next part of the article presents effective microorganisms, i.e. what they are and how they work, in particular, their composition and appropriate development conditions. In addition, some of their specific applications were briefly described. In the next part of the article, the research methodology, applied oil samples with additives of effective microorganisms, both for fresh oil and used oil were described. In addition, the measuring test stand with instrumentation and measuring device was shown. The main part of the article contains the characteristics of dynamic viscosity as a function of temperature for fresh oil and used oil compared with oils with the addition of microorganisms in liquid form and ceramic tubes. The developed graphs enabled analysis of the effect of the addition of microorganisms on oil viscosity as ecological products.

Schlüsselwörter

  • petroleum products
  • oil viscosity
  • engine oil
  • microbiological contamination
  • effective microorganisms
Uneingeschränkter Zugang

Wind Tunnel Tests of the Tu-154M Aircraft Aerodynamic Characteristics

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 113 - 120

Zusammenfassung

Abstract

Determination of possible manoeuvres to be performed by the aircraft requires knowledge of its aerodynamic characteristics including, in particular, characteristics of the aircraft at configuration with deflected control surfaces. In this article, the wind tunnel tests results of the model of passenger Tu-154M aircraft manufactured at the scale 1:40 are presented. The model was designed and manufactured by the Military University of Technology based on the Tu-154M aircraft geometry obtained by full-scale object scanning. The model mapped all aircraft control surfaces, along with the gaps between these surfaces and the main wing part.

During the tests all the model’s control surface like, flaps, ailerons, spoilers, slots, rudder, elevator and tail plane were deflected at the same deflection angles range as they are used in the full scale aircraft. The aerodynamic characteristics of the tested Tu-154M aircraft model were measured by the 6-component internal balance. Based on the obtained measurements the aircraft model aerodynamic coefficients were calculated. In the article the basic aerodynamic characteristics of the tested Tu-154M aircraft model i.e. lift, drag coefficients as well as pitching, yawing and rolling moment coefficients versus model angles of attack and sideslip angles were presented.

The tests were performed in the Institute of Aviation low speed wind tunnels T-1 of the 1.5 m diameter test section at the undisturbed velocity, V∞ = 40 m/s.

Schlüsselwörter

  • applied aerodynamics
  • tests reliability
  • aerodynamic measurements
Uneingeschränkter Zugang

Models of the Reference Departure and Arrival IFR Procedures for the Purpose of Research in RPAS Integration in Controlled Airspace

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 121 - 128

Zusammenfassung

Abstract

The air operations in controlled airspace performed according to Instrument Flight Rules (IFR) are composed of three main flight phases, i.e. departure, cruise, arrival. Controlled airspace is divided into the terminal area and en-route airspace. The terminal area encloses the departure and arrival phases while the en-route airspace encloses the cruise phase. The IFR procedures are designed for manned aviation to ensure the safety of air operations. Development of the aviation concerns among others the increase in the number of unmanned aviation operations. Currently, on the European level, there is an on-going, long-term program of integration of the unmanned aviation in the uniform (non-segregated) airspace. This work concerns the research in the integration of the Remotely Piloted Aircraft Systems (RPAS) in the IFR procedures of the controlled airports. The objective was to build the reference models of Standard Instrument Departure and Arrival Procedures (SID and STAR). Basing on the procedure design guidelines the models of procedural nominal track, tolerance area, obstacle clearance area, climb or descend gradient, manoeuvres in SID and STAR were done. The guidelines describe the operational minima thus the statistics of existing procedures was done to select the suitable procedure parameters such as a number of navigational points, segments lengths, altitudes, climb or descent gradients. Reference models of SID include straight departure and turning departure procedures. Reference models of STAR include non-precision approach procedures according to used navigational aids, i.e. GNSS, VOR. The reference procedures were numerically implemented which will be used in the further works on RPAS integration problem by simulations of the RPAS ability to execute of the SID and STAR.

Schlüsselwörter

  • RPAS integration
  • SID and STAR
  • unmanned aviation
  • controlled airspace
  • controlled airports
Uneingeschränkter Zugang

The Full or Partial Replacement of Commercial Marine Engine Oil with Bio Oil, on the Example of Linseed Oil

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 129 - 135

Zusammenfassung

Abstract

The bio-oils are considered to sustainable, alternative and environmentally friendly source of lubricants compared to commercial engine oils, on the base a mineral, synthetic or semi-synthetic. They are obtained from natural raw material (vegetable or animal oils), which are renewable and non-toxic to humans, living organisms and environment. The vegetable oils called green oils, natural oils, bio-oils or natural esters. They can be obtained from plant seeds, that may be consumed – edible oils (for instance: rapeseed oil) or which cannot be consumed – inedible (for example: linseed oil).

The conducted research into linseed oil and its different quantity additives (25% and 50%) to commercial marine mineral oil intended for a medium-speed 4-stroke, trunk marine engine (i.e. Marinol RG 1240). The flash point and dependence of viscosity and temperature were compared and assess. It has been proven that vegetable oils have a high ignition temperature and very small viscosity change in the range of temperatures presented, i.e. high viscosity index.

According to the results, it can be recommended the addition of 25% linseed oil in the base lubricant is the relevant for lubricating a medium speed 4-stroke marine engine. The vegetable additives can improve a viscosity index a lube oil, and they will be positively affected environmental protection.

Schlüsselwörter

  • bio-lubricant
  • vegetable oil
  • linseed oil
  • engine oil
  • marine
  • mineral oil
  • inedible oil
  • viscosity
  • flash point
Uneingeschränkter Zugang

Characteristics of Carbon Dioxide and Product Water Exhausts in a Direct Methanol Fuel Cell with Serpentine Channels

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 137 - 144

Zusammenfassung

Abstract

This study utilized a transparent direct methanol fuel cell, with serpentine channels with a width of 2 mm and an initial depth of 2 mm, and investigated the relationship between the behaviours of carbon dioxide (CO2) slugs, product water accumulations, and voltage fluctuation. It examined the exhaust volumes of CO2 slugs and product water accumulations from the channels over time, comparing an anode channel with a depth of 1.2 mm to one with a depth of 2 mm (without changing the cathode depth of 2 mm, nor the width of 2 mm in both the anode and the cathode). Results indicated that cell voltage fluctuated, rising while CO2 slugs were ejected, and falling between ejections. In the case of an anode channel depth of 2 mm and a lower methanol-water solution flow rate, CO2 slugs were ejected less frequently, so cell voltage fluctuated widely. (Product water accumulations in the cathode had a minimum effect on this cell voltage fluctuation.) In the case of a higher methanol-water solution flow rate, CO2 slugs were ejected more frequently, with less exhaust volume per CO2 slug, reducing the fluctuation in cell voltage. Finally, with an anode channel depth of 1.2 mm, the exhaust volume per CO2 slug became even smaller, and these small CO2 slugs were rapidly ejected. With this shallow depth, the cell voltage increased with a lower methanol-water solution flow rate, but decreased with a higher methanol-water solution flow rate by crossover.

Schlüsselwörter

  • direct methanol fuel cell
  • bubble of carbon dioxide
  • slug of carbon dioxide
  • product water
  • transparent cell
  • serpentine channel
Uneingeschränkter Zugang

Planning the Flight Trajectory of a Passenger Aircraft with Regards to the Aspect of Pollutants Emission

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 145 - 153

Zusammenfassung

Abstract

One of the ways to reduce the adverse impact of aircraft on the environment is through the determination of the trajectory of the flight on a given route that leads to reducing fuel consumption and, consequently, emission of pollutants in jet engines exhausts. Planning a flight in terms of minimizing emissions or fuel consumption is a complex task and difficult to implement due to the conditions in which the aircraft travels, but it is possible though. It is necessary to take into account the limitations resulting from the organization of the airspace and the rules therein, as well as the current weather conditions. The weather is one of the main factors determining the amount of fuel consumed, the time and cost of a particular flight on a given route. In addition to the main parameters, such as pressure and air density, it is extremely important to determine the air temperature, as well as the wind speed and direction. The temperature affects the speed of sound, based on which it is possible to determine the Mach number for a plane flying with a given true air speed (TAS). The speed and direction of wind, on the other hand, affect the speed of the aircraft relative to the ground (velocity over ground, VOG), and thus the duration of its flight. The article describes how the developed model of emission of pollutants in the exhausts of jet bypass engines can be useful for determining the trajectory of an aircraft in its cruise phase due to the criterion of pollutants emissions minimization. An exemplary analysis was carried out for selected aircraft moving along the route adopted for the research. The analysis covered various cruising altitudes and various meteorological conditions (wind speed and direction). The obtained results are illustrated graphically and discussed.

Schlüsselwörter

  • aircraft
  • emission
  • cruise phase
  • flight trajectory
Uneingeschränkter Zugang

Determination of CO2 Emissions for Selected Flight Parameters of a Business Jet Aircraft

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 155 - 163

Zusammenfassung

Abstract

In the last two decades, there has been observed a noticeable increase in the popularity and availability of air transport services, including regional ones. This intensive development of transport is accompanied by an increase in the adverse impact to the environment, increases noise level, and exhausts emissions, despite the modification and modernization of engines. Determining the emission for regional flights takes into account the specificity of the aircrafts design, such as the size of the aircraft and the performance of the engines. In this article, an attempt was made to determine the CO2 emissions of a business jet flying from Gdansk to Rzeszow. The methodology of the research (the method of calculating emissions based on fuel consumption) and the performance characteristics of the aircraft engines have been described. In the first part of the article, the speed-altitude characteristics of the DGEN-380 engine for different cruise parameters were determined using the virtual engine test bench WESTT CS/B. These characteristics have enabled the engine to match the flight characteristics (altitude, speed). For specific flight parameters, the thrust and fuel consumption were determined. On this basis, for the adopted trajectory and flight time of an aircraft equipped with two DGEN-380 engines, total fuel consumption and CO2 emission factors and values in CRUISE phase was determined with regard to the wind speed and direction. The obtained results were illustrated graphically and discussed.

Schlüsselwörter

  • CO emissions
  • jet engines
  • business jet aircraft
Uneingeschränkter Zugang

Turbulent Triggers and the Model Quality Influence on Aerodynamic Characteristics of the Laminar Aerofoil in Transonic Flow Regime

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 165 - 172

Zusammenfassung

Abstract

The test with a roughness application on the laminar aerofoil has been conducted in the N-3 trisonic wind tunnel of the Institute of Aviation in Warsaw. The main goal of tests was to investigate the influence of the boundary layer transition triggers on a laminar profile aerodynamic characteristic. For baseline configuration, the natural transition was applied. As a local roughness on the upper model surface, the carborundum strips with different heights were applied. These were positioned on the upper model surface in the front of the shock position occurrence. The Mach number during test was equal Ma = 0.7 and Reynolds number was about 2.85·106. Tests have been conducted for different model incidence in range 0°-7°. Current article refers partially to the previous study, where aerofoil model with lower quality of surface had been tested. Investigation results from previous work indicated that some of transition positions improved an aerodynamic characteristic by reducing the drag coefficient value and decreasing shock wave unsteadiness in the transonic regime. However, current article indicates that beneficial effects in respect to the baseline configuration are also strictly dependent on the model quality and turbulent triggers size. Improved surface quality of the laminar aerofoil model affected on aerodynamic characteristics with and without turbulent triggers. Resultant aerodynamic coefficients of all tested cases i.e. drag, lift and lift to drag ratio were compared.

Schlüsselwörter

  • transonic flow
  • aerofoil
  • model quality
  • aerodynamic characteristics
  • shock wave
Uneingeschränkter Zugang

Analysis of Ratios of Propulsion Energy Demand for Transport by Bulk Carriers

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 173 - 180

Zusammenfassung

Abstract

The article presents the results of calculations and analysis of the eM ratio of the propulsion energy consumption per the nautical mile and the eMt ratio of the propulsion energy demand for the transport of 1-ton cargo per the nautical mile for bulk carriers. The relationship between eM and eMt indicators with the EIV (Estimated Index Value) ratio is shown. The output data for the determination of eM and eMt indicators was taken from the quoted MAN publication, reading (reproducing) the values of power, velocity v and DWT tonnage from the charts included in this publication. Calculations and analyses were made for velocity v between 11-15 knots and for DWT from 5-400 kt (kilo tonnes). The graphs of eM and eMt ratios in the function of speed v and load capacity DWT are presented. Using the stepwise method of least squares, models of statistical dependence of indicators on velocity v and load capacity of bulk carriers were developed. They were based on generalized polynomials with integer exponents. Derivatives deM / dv and deMt / dv and derivatives deM / dDWT and deMt / dDWT were determined. The main observations resulting from the conducted analyses are observed with the increase of DWT (within the range of 80-100 kt) a significant decrease in the value of the eM index. For DWT values> 100 kt, the decrease in eMt is slow − eMt asymptotically tends to a constant value. The results of the analyses carried out can be used at the stage of designing the transport capacity (tonnage) and nominal speed of the ship as well as selection of ship tonnage and travel speed in a given transport situation.

Schlüsselwörter

  • bulk carriers
  • transport
  • ratio of energy consumption per Nautical Mile
  • ratio of energy consumption per Nautical Mail and per one ton of DWT
Uneingeschränkter Zugang

Influence of Heat Treatment on Corrosion Properties of Non-Alloy Steel in Acidic Environment

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 181 - 188

Zusammenfassung

Abstract

The article presents the influence of heat treatment on corrosion properties of non-alloy steel. This steel is used in machine elements. Heat treatment has a major impact on corrosion resistance of steel materials. Laboratory methods for measuring the corrosion rate consist of Electrochemical Impedance Spectroscopy and polarization curves. Instead of these types, there are also industrial methods of velocity corrosion measurements like researches in natural conditions and coupons corrosimetry. These days the most popular techniques of corrosion measurements are electrochemical measurements. In order to conduct impact assessments influent of heat treatment to corrosion properties there is need to proceed few steps like prepare samples, carry out heat treatment, hardness measurements, metallographical examination, prepare samples for corrosion and proceed corrosion researches by potentiodynamic method. An important element during researches is corrosion allowance, which has an impact influent on corrosion properties. This is the most popular and efficient method of corrosion protection. These days for corrosion protection are use paints or zinc coatings, cathode protection or stainless.

Schlüsselwörter

  • corrosion process
  • non-alloy steel
  • corrosion preventive coatings
  • heat treatment
  • corrosion allowance
Uneingeschränkter Zugang

Problems of an Aerodynamic Interference between Helicopter Rotor Slipstream and an Elevated Heliport

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 189 - 196

Zusammenfassung

Abstract

An elevated heliport, as it has been defined by FAA (Federal Aviation Administration), is a heliport located on a rooftop or other elevated structure where the TLOF (touchdown and lift-off area) is at least 30 inches (76 cm) above the surrounding surface [1]. One of greatest advantages of such heliports is that they require less free space, which eases its build nearby existing buildings – especially in densely built-up areas. However, design of such heliports is more complicated, than ground level ones, while one must include an aerodynamic impact of the building below the elevated heliport and surrounding buildings. The aerodynamic interference between the helicopter and the buildings may result with decline of flight safety, due to sudden decrease of thrust (when flying above the edge of building) or because of increased turbulence in windy weather, wake behind surrounding buildings causing sudden gusts etc. Moreover, oscillations of pressure caused by helicopter rotor influence on the building structure also must be taken into account due to increased wear of upper part of the building or devices mounted on its roof (for example, elevator drives). These oscillation may also cause vibrations of building’s structure, which is especially important in case of medical heliports – which are a vast majority of elevated heliports (and heliports in general) – because of strict requirements for acceptable vibration level. The article is aimed on summarize aerodynamic issues, which should be taken into account during design of elevated heliport.

Schlüsselwörter

  • transport
  • helicopter flight safety
  • rotor wake
  • elevated heliport
Uneingeschränkter Zugang

Cooled Turbine Cantilevered Nozzle Mounting and Sealing System

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 197 - 202

Zusammenfassung

Abstract

Small advanced turboprop and turboshaft engines, with two-stage high-pressure turbine (HPT), need to meet several challenges. Described herein is an exemplary solution adopted for a cantilevered HPT nozzle mounting and sealing system that helped to meet requirements for size constraint and sealing of split lines and mounting features. Since clearances do not scale down with engine size due to manufacturing tolerances, there is a very limited space available between first and second stage rotors to secure HPT nozzle and to provide means of cooling air supply. Due to small diameters, cavities and size of the parts and assembly access becomes very difficult and precluded the use of typical solutions – like supply air spooilers – known from bigger engines. Relatively larger clearances require also efficient solution for sealing leakage, which was achieved by means of high-temperature braided “rope seals”. The nozzle segments have weight effective hook-type outer band mounting to HPT outer casing and are axially retained by HPT shroud with a snap ring. The hook cavities were used as pockets for rope seals that are subsequently compressed during assembly making it more difficult. However, by special design of the pockets and parts engagement sequence, the assembly process was optimized even though it is so called blind assembly. The sealing system function is not only reducing leakages that are detrimental to a turbine efficiency, but also allow for pressurizing the cavity between the nozzle outer band and HPT outer casing with cooling air thus preventing from hot gas ingestion by higher back-flow margin (BFM) resulting in higher durability of the turbine.

Schlüsselwörter

  • transport
  • gas turbine
  • cooled turbine
  • cantilevered nozzle segment
  • sealing
Uneingeschränkter Zugang

Particulate Matter Emission Reduction from Marine Diesel Engines by Electrohydrodynamic Methods

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 203 - 210

Zusammenfassung

Abstract

Particulate matter (PM) and gaseous compounds (SO2, NOx, VOC) emitted by diesel engines causes serious global environmental problems and health impact. Despite numerous evidences about the harmfulness of diesel particles, the PM emission by diesel engines used by ships, cars, agricultural machines, or power generators is still unregulated, and the efficient removal of PM from diesel exhausts is still the major technological challenge. In order to comply with the International Maritime Organization regulation, the NOx emission is reduced by using selected catalytic reactor, and sulphur oxide emission has been reduced by using fuels of low sulphur content. However, both of those measures cannot be used for the reduction of PM emission produced during combustion of marine fuels. The lack of appropriate regulations results from insufficiently developed technology, which could remove those particles from exhaust gases. Conventional scrubbers currently available on the market remove only sulphur oxide with required collection efficiency, but the collection efficiency for PM2.5 is below 50%. The article discusses the technical means used for the removal of PM from marine diesel engines via applying electrohydrodynamic methods, in particular electrostatic agglomeration, as a method of nanoparticles coagulation to larger agglomerates, which could operate in two-stage electrostatic precipitation systems, and electrostatic scrubbers, which remove particles by electrically charged water droplets. The experimental results were obtained for a 2-stroke 73 kW diesel engine fuelled with marine gas oil (MGO). The agglomerator allowed increasing the collection efficiency from diesel exhausts for PM2.5 particles by about 12%, compared to electrostatic precipitator operating without agglomerator, and the total mass collection efficiency was above 74%. The collection efficiency of electrostatic scrubber was higher than 95wt.%. The advantage of using the electrostatic scrubber is that it can also reduce the SO2 emission by more than 90%, when HFO is used.

Schlüsselwörter

  • exhaust gases
  • marine diesel engines
  • particulate matter (PM)
  • scrubber
Uneingeschränkter Zugang

Helicopter Flight Simulation based on URANS Solver and Virtual Blade Model

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 211 - 217

Zusammenfassung

Abstract

The methodology of simulation of a rotorcraft flight has been developed and applied to simulate several stages of flight of light helicopter. The methodology is based on coupling of several computational models of Computational Fluid Dynamics, Flight Dynamic. The essence of the methodology consists in calculation of aerodynamic forces acting on the flying rotorcraft by solving during the simulation the Unsteady Reynolds-Averaged Navier-Stokes (URANS) equations. In this approach, the rotorcraft is flying inside the computational 3D mesh modelling the space filled with the air. The flight simulation procedure is completely embedded in the URANS solver ANSYS FLUENT. Flow effects caused by rotating blades of main or tail rotor are modelled by application of the developed Virtual Blade Model (VBM). In this approach, real rotors are replaced by volume discs influencing the flow field similarly as rotating blades. Time-averaged aerodynamic effects of rotating blades are modelled using momentum source terms placed inside the volume-disc zones. The momentum sources are evaluated based on the Blade Element Theory, which associates local flow parameters in the blade sections with databases of 2D-aerodynamic characteristics of these sections. Apart of the VBM module, two additional UDF modules support the simulation of helicopter flight: the module responsible for modelling of all kinematic aspects of the flight and the module gathering the momentary aerodynamic loads and solves 6 DOF-Equations describing a motion of the helicopter seen as solid body. Exemplary simulation of helicopter flight, starting from a hover, through an acceleration and fast flight until a deceleration and steep descent, has been discussed.

Schlüsselwörter

  • helicopter flight simulation
  • URANS
  • Virtual Blade Model
Uneingeschränkter Zugang

Influence of Seawater Salinity on Corrosion of Austenitic Steel

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 219 - 225

Zusammenfassung

Abstract

Due to the paramagnetic properties and the ability to passivation, for the production of hulls of some vessels (mainly warships), corrosion-resistant (stainless) steels with austenitic structure are used. This article describes the influence of seawater salinity on selected corrosion properties of high-alloy steel X5CrNi 18-10 (304). The average salinity of the seas is taken as 3.5% content of sodium chloride. Corrosion rate of the tested material was evaluated in an aqueous solution of sodium chloride was evaluated. The NaCl concentration in corrosive solutions was 0.7%, 1.4%, 2.1%, 2.8%, 3.5%, 4.2%. Corrosion tests were performed using the potentiodynamic method. The range of electrochemical potential changes was Ecorr ±150 mV. Corrosion rate was assessed on the basis of corrosion current density measurements. Corrosion potential values against the saturated calomel electrode were also determined. Based on the obtained measurement results and non-parametric significance tests carried out, a significant influence of seawater salinity on the value of corrosion current density and corrosion potential was found. The highest value of corrosion current density (jcorr), and thus the highest corrosion rate, was recorded for 3.5% NaCl solution. In the concentration range from 0.7 to 3.5% NaCl in solution, the corrosion rate of austenitic steel increases. A further increase in salinity of electrolyte results in the inhibition of corrosion rate of steel. There is almost a full negative, linear correlation between the proportion of sodium chloride in the corrosive solution and the value of corrosion potential. Along with the rise in the salinity of seawater, increase the electrochemical activity, and thus the corrosion susceptibility, thus the corrosion susceptibility, of the austenitic steel X5CrNi 18-10 was observed.

Schlüsselwörter

  • austenitic steel
  • corrosion
  • potetiodynamic test
  • seawater
Uneingeschränkter Zugang

Reducing Emission of Harmful Toxic Substances by Trucks in the Aspect of Analysis of Selected Vehicle Operating Parameters and Human Factor

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 227 - 234

Zusammenfassung

Abstract

Digital tachographs as devices recording the work of a lorry and driver’s work are a constant factor in the work of a professional driver. It is therefore important to preserve the security of recording and storing electronic information. In this matter, cryptography also becomes an inseparable field of science. The control services set up to conduct roadside inspections do not detect all violations in the recording devices by encrypting information in information systems. One of the frequent vehicle operating parameters that can be falsified are the speed of the vehicle and its rotational speed, as well as the time and efficiency of the driver’s work. These parameters affect the amount of fuel consumption. The reduction of fuel consumption translates directly to the reduction of harmful substances emitted by the car to the environment. Variable compression engines are becoming the future of motoring in the case of internal combustion engines. It is noticeable that there are more frequent deliberate of regulations; and more violations rules concerning the proper functioning of recording devices by recording driver activity. Current methods of preventing violations are insufficient. The article points out the violations related to the actual rotational speed of the crankshaft of the internal combustion engine in relation to the vehicle speed profile, which is directly related to the fuel consumption and the emission of harmful substances. The article describes the ways to reduce fuel consumption, of which the correct driving technique is important in addition to the previously marked parameters. The factors that increase the awareness of professional drivers in the aspect of proper driving techniques are described.

Schlüsselwörter

  • eco-driving training
  • rotation speed
  • digital tachograph system
  • recording equipment
  • road transport
Uneingeschränkter Zugang

Strength Analysis of Polymer Conical Gear Wheel Made with 3D Printing Technique

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 235 - 242

Zusammenfassung

Abstract

The article deals with the problem of designing conical gears with a curved line contour. The contour of the tooth flank is described by means of a helix and involutions. In the work, a conical gear designed to drive of the lower limb rehabilitation exoskeleton has analysed. Parameters of the conical gearbox have been adapted to design requirements of the exoskeleton. Gear wheels were made with ABS material using 3D printing technique. The article presents the results of strength calculations obtained using the method classical design of the gear wheals described in the norm ISO 6336-1996. In the strength calculations, bending and contact stresses were taken into account. Creating the contour of gears was aided through the gearbox wizard available in Inventor program. The work contains the results of a static tensile test of the material from which the gear wheels were made. In experimental and numerical studies, the orthotropy of the material used was taken into account. The orthogonal values of the Young’s modulus, the Poisson’s ratio and the Kirchhoff’s modulus were determined. The publication also includes partial results of fatigue tests in the area of normal stresses. In the research used to finite element method (FEM), determine of internal loads in the gear. A structure of the FEM model is described in detail. Maximum values of contact pressures determined by use to FEM models have been compared with the results obtained on the basis of Hertz’s formulas. The article presents basic geometrical and strength parameters of the designed gear. The work demonstrates the validity of the material models used. Limitations in the application of the classic method of calculating conical gears made of orthotropic materials have been indicated. The results of analytical and numerical calculations are presented in tabular and graphical form.

Schlüsselwörter

  • Exoskeleton
  • strength analysis
  • finite element method (FEM)
  • material model of acrylonitrile-co-butadiene-co-styrene
  • conical gears
Uneingeschränkter Zugang

The Process of Regenerative Heat Treatment of the Valve Chamber of the Steam Turbine

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 243 - 248

Zusammenfassung

Abstract

Steel castings are often used in the construction of valve chambers of steam turbines. Stringent requirements are set due to the continuous operation of the material at elevated temperatures, in the order of 300°C to 600°C. The material of the valve chamber must be resistant to fatigue-creep changes as well as corrosion. This material must be also resistant to dynamic damage which occures when the turbine is starting and stopping. Dynamic damage is induced by a short-lasting but intense accumulation of localized stresses. The castings of the valve chambers of the steam turbine are usually made from the “three-component” type CrMoV-cast steel. Mentioned castings of the valve chamber are continuously subjected to high temperatures, either constant and periodically variable stresses. Due to this, the degradation process of material of the castings is taking place. It is caused by physicochemical processes such as: creep, relaxation, thermal fatigue, corrosion, erosion and changes in material properties, e.g. displacement of the critical point of brittleness. Finally, first cracks and deformations can be observed in the material during the operation. The art presents the process of revitalization technology of the steam turbine valve chamber which was subjected to long-term operation at high temperatures. The revitalization process is aimed at improving the plastic properties of the material and, as the result, extending its service life. The research presented in the article show that impact strength of the chamber material after revitalization is very high. Also the strength properties of the valve chamber, after revitalization, are high and in line with the requirements. The study show that the revitalization of the valve chamber was carried out correctly and restored the material to plastic deformation.

Schlüsselwörter

  • regenerative heat treatment
  • valve chamber
  • steam turbine
Uneingeschränkter Zugang

Research the Possibility of Obtaining Diagnostic Information about the Ships Engine Fuel Injection System Condition based on the Analysis of Characteristics of Heat Release

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 249 - 256

Zusammenfassung

Abstract

Marine engines are very complex technical objects, having many important functional systems, which include, inter alia, injection system, characterized by high unreliability. In this system, there may be different types of defects (damage) that affect the engine parameters, including specific fuel consumption, as well as failures endanger the safety of the ship. The indicator diagrams and analysis of indicated parameters have limited utility in the diagnosis of damages of marine engine, although this is a method commonly used in operational practice. To achieve greater diagnostic effectiveness, when, based on indicator diagrams, are calculated and then the characteristics of heat release is analysed - net of heat release characteristics and the intensity of the heat release, it was demonstrated. This procedure is particularly effective in the diagnosis of damages of marine diesel engine injection system components. It has been shown that the characteristics of heat release contain information about the condition of the injection systems, which enable to diagnose their failures. This is shown on the example of a clogged nozzle holes (their carbonizations). The obtained results allowed selecting the diagnosis symptoms, useful in detecting these faults in the injection system, from the characteristics of heat release: net heat release (Q) and intensity of heat release (q). The object of the research was typical marine medium speed engine Sulzer A25/30.

Schlüsselwörter

  • marine diesel engine
  • indicated parameters
  • indicator diagram
  • heat release characteristics
  • injection system
  • diagnostic
Uneingeschränkter Zugang

A Prototype Test Stand for Testing Insolated Rotor Systems

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 257 - 264

Zusammenfassung

Abstract

The article discusses assumptions for a prototype test stand designed for testing rotors in the conditions of work at their nominal speed, in particular gyrocopter and helicopter rotors. In the work presents an overview of similar solutions of test stand presented in the available literature and solutions proposed by companies, such as Swangate International or Luftfahrttechnik GmbH. Beyond these solutions the article also contains test stand used so far at the Institute of Aviation, these solutions were prepared for testing one type of rotor (for example: only for gyroplane rotors). The article provides the steps of designing a new test stand, which one of the basic assumptions is that it will be a universal test stand, giving the possibility to test different types of rotors. The article discusses two concepts of the stand with electric engine as a drive, gives the advantages and disadvantages of each concept, and indicates the selected solution. In addition to design and applied drive solution of the stand, the measuring part and data acquisition were also discussed. Moreover, the article focus on the advantages of rotor testing using the presented solution, as well as problems encountered during tests, in particular related to construction free vibrations and resonance. Vibration and resonance of the test stand are very important aspect of the entire design process, because it affects the quality and safety of the tests.

Schlüsselwörter

  • test stand
  • main rotor
  • design
  • construction resonance
Uneingeschränkter Zugang

Gyroplane Rotor Hubs Strength Tests

Online veröffentlicht: 10 Oct 2019
Seitenbereich: 265 - 270

Zusammenfassung

Abstract

In this article a review of rotor, hub constructions were presented. Discussed rotor’s hub is made of composite or aluminum alloys materials. Two types of rotor hub were presented (four-blades and two-blades teetering rotor hub), each of them are dedicated to gyroplanes. Typical gyroplane main rotors are characterized by simple design, especially in case of rotors for light gyroplanes. In the following part of the article the type of strength tests required by certification process were shown. The test programs based on legal aspects of admission to the flight tests taking into account legislation such as CS 27 (Subpart C – Strength Requirements), CAP 643 British Civil Airworthiness requirements Section T Light gyroplanes, ASTM F2972. Furthermore, this article discusses strength tests of gyroplane rotor hub such as measured parameters, methodology of measurement, types of sensors, course of test, test stands, and limit loads. The loads during “pull-up from level flight” manoeuvre are limit loads during tests. Required additional processes, like a verification the same parameters by two types of method were shown i.e. deformation of structure were tested by strain gauges and reverse engineering. Strength tests had to be made before flight test, based on results of them aircrafts are flight authorized. In conclusion, the results of tests were presented and fulfilment of legal assumptions and requirements were shown.

Schlüsselwörter

  • gyroplane
  • strength tests
  • rotor hub
  • aviation regulations

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