This paper proposes the use of vibroacoustic signal parameters to estimate the fuel consumption of a miniature GTM-400 engine. The method for testing engine vibrations is presented, followed by an analysis of the results obtained. Two vibration point measures were selected to build a fuel consumption model. The models obtained were verified, after which those that best describe the real fuel consumption of the engine were selected. The paper proves that the vibration signal, in addition to its applications in jet engine diagnostics, can be used to determine engine performance, which can contribute to reducing the complexity of construction and increasing the economics of engine operation.
2
Dostęp do pełnego tekstu na zewnętrznej witrynie WWW
The thermodynamical simulation predicts the phase transformation of M7C3 to M23C6, proven previously via electron microscopy. Some other reported experimental works suggest that this can also take place also during heating [22, 45, 46]. Considering this, the melting process of the primary M7C3 carbide can be that the M7C3 first undergoes a phase transformation into M23C6 and then melts, instead of directly melting. A similar conclusion was given by Gui et al. [47-49] based on experiments on the Co-based superalloy strengthened (in as-cast condition) by M7C3 and MC carbides. It was suggested that the creation of the liquid phase follows the reaction M23C6 + α→L. The reaction was initiated on the M23C6/α interface and proceeded towards the center in the range of 1280 - 1348 ˚C. Before melting, the MC eutectic carbide degenerated, and its morphology changes to a well-rounded shape. Exceeding 1400 ˚C leads to the melting reaction of MC + α→L in the X-40 Co-based superalloy.
3
Dostęp do pełnego tekstu na zewnętrznej witrynie WWW
The X-40 Co-based superalloy is often used in the aerospace industry directly in as-cast condition and its analysis in this state is essential to understand further possible phase transformations during service. With this in mind, this work focuses on characterizing the material’s as-cast microstructure, phase transformation temperatures and oxidation resistance. Observations and analyses were performed via thermodynamic simulations, X-ray diffraction (XRD), light microscopy (LM), scanning electron microscopy (SEM), scanning-transmission electron microscopy (STEM-HAADF), energy-dispersive X-ray spectroscopy (EDX), dilatometry (DIL) and differential scanning calorimetry (DSC). The microstructure of the dendritic regions consisted of the α matrix, with MC, M7C3 and M23C6 carbides being present in the interdendritic spaces. Based on DIL, it was found that precipitation of the Cr-rich carbides from the saturated α matrix may occur in the range 650-750 °C. DSC determined the incipient melting and liquidus temperatures of the X-40 superalloy during heating to be 1405 °C and 1421 °C, respectively. Based on oxidation resistance tests carried out at 860 °C, it was found that the mass gain after 500 h exposure was 3 times higher in the air than in steam.
Biofuel use is one of the basic strategies to reduce the negative impact of aviation on the environment. Over the past two decades, a number of biofuels produced from plants, lubricants and maintenance products have been developed and introduced. New fuels must have specific physicochemical parameters and meet stringent standards. his article presents a comparative analysis of the exhaust emissions measurement results from jet engines powered by traditional aviation kerosene and its blends with ATJ (Alcohol to Jet) biofuel. The concentrations of carbon dioxide, carbon monoxide and hydrocarbons were measured. Measurements were conducted in laboratory conditions for various engine load values. Based on the analysis, it was found that the use of biofuel increases the concentration of carbon monoxide and hydrocarbons in the exhaust gas relative to aviation kerosene. The use of biofuel did not result in an increase in fuel consumption and related carbon dioxide emissions. Based on the conducted research, it was found that biofuel use did not affect the ecological properties of the engine significantly. In addition, a correlation analysis of the measurement results from both engines was carried out.
The paper presents the effects of the application of an experimental impulse test as a method of diagnosis of the technical condition of an SO-3 engine turbine blade fitted in a TS-11 Iskra aircraft. The aim of the test was to investigate the frequency characteristics of the blades and discuss differences between the frequency spectrum of the investigated component before and after its damage. The acoustic response measurements were performed to the signal generated by an impact hammer on the fully functional and intentionally damaged blades. The recorded signals were converted from the domain of time to the domain of frequency using the Fast Fourier Transform (FFT). The results of the FFT were the Frequency Response Functions (FRF) of the sound of the blades, based on which the statistical analysis of the resonance frequencies was carried out. The influence of the mechanical damage of the blade on the shape and characteristics of the frequency spectrum was confirmed, which substantiated the effectiveness of the impulse test in the diagnostic assessment of jet engine components.
Ograniczenie emisyjności szkodliwych związków, takich jak CO 2 i NOx, zostało uznane za priorytetowy cel w Unii Europejskiej. W lotnictwie, które jest jedną z branży o wysokim wskaźniku wytwarzania zanieczyszczeń, ograniczenie emisji zanieczyszczeń można uzyskać przez zastosowanie elektrycznych silników odrzutowych. Silniki takie konstrukcyjnie znacznie różnią się od silników napędzanych naftą lotniczą. Związane jest to przede wszystkim z wykorzystaniem energii elektrycznej jako źródła zasilania. W artykule przedstawiono koncepcję elektrycznego silnika odrzutowego, w którym wirnik łożyskowany jest magnetycznie. Zaprezentowano opracowane w Zakładzie Awioniki Instytutu Techniki Lotniczej WAT demonstratory technologii aktywnych i pasywnych łożysk magnetycznych, jak i bezłożyskowych silników elektrycznych, a także technologię zasilania hybrydowego z wykorzystaniem ogniw paliwowych.
EN
Reducing the emission of harmful compounds such as carbon dioxide and nitrogen oxides has been identified as a priority target in the European Union. Aviation is one of the main sources of pollution. The reduction of pollutant emissions can be achieved by the use of the electric jet engine. This type of a jet engine differs significantly from a kerosene-powered engine. The article presents the concept of an electric jet engine with the rotor that is magnetically suspended. Demonstrators of active and passive magnetic bearing technologies and bearingless electric motors, developed at the Avionics Department, are presented in the paper.
The menace of surge occurrence in the compressors is taken very seriously and its avoidance became a fundamental for the design of any modern jet engines. Nowadays, a problem with appropriate evaluation of the compressor surge margin while considering different simplifications of three-dimensional CFD model is still present. For that purpose, this article presents a comparison between the measurement data and several variants of 3D CFD models characterized by a specific mesh density. To calculate all the results on which the comparisons and conclusions are based, an 8-stage axial compressor is taken into account. Flow conditions of the machine are computed for three part load speeds: The low, the mid and the high one respecting the variable guide vanes schedule fitted to the specific load. For each of speed variants a four mesh configurations were generated: coarse, medium, fine and extra-fine. All speed configurations were treated with two different turbulence models – Wilcox k-ω and Menter’s SST k-ω, giving ultimately 15 CFD models, calculated with the TRACE solver using an initialization based on a circumferentially averaged flow solution delivered by the Streamline Curvature Method. During the study an additional assessment of reference grid independence was performed and the mesh convergence has been achieved. A comparison between turbulence models and the measurement proves that SST turbulence model is not well distributed through the speeds in compare to the measurement data and the Wilcox turbulence model. Inconsistency of sensitivity in the mesh coarsening for different rotational speeds was found. Increasing the mesh roughness level has to be executed for each speed separately. Overall compressor map shows that shift of the Pressure Ratio and the Mass Flow decreases with lower rotational speed. Neglecting the system add-ons like labyrinth sealing volumes, bleed-ports and other leakages has a visible influence on deviations from the measurements. Because of intended future use in design and optimization the “Medium” grid with Wilcox k-ω turbulence model was chosen, being a good representation of the Rig characteristics with reduction of the computing time.
W artykule przedstawiono wyniki badań numerycznych nad możliwością zastosowania sztucznych sieci neuronowych (SSN) do obliczeń wytrzymałościowych elementów maszyn wirnikowych. W tym celu autorzy rozważyli kilka prostszych przypadków w celu ustalenia optymalnej struktury SSN i odpowiedniego sposobu jej uczenia. W pracy przedstawiono wyniki dotyczące uczenia sieci rozwiązywania problemu belki wysięgnikowej. Następnie analizowano problem ważkiej tarczy prostej obciążonej ciągnieniem w celu doboru modelu SSN. Ostatnim analizowanym zagadnieniem było zastosowanie SSN do wyznaczania rozkładu naprężeń w profilowanej tarczy sprężarki osiowej.
EN
In this paper the results of numerical research in possibility of usage artificial neural network (ANN) in stresses analysis are presented. For this purpose, a few simple cases were considered in order to optimize the ANN structure and its learning algorithm. In the first part of this paper, results of learning ANN of solving the cantilevered beam problem are shown. The simplified compressor disc problem was analyzed due to select the ANN model. The last case is the use of ANN to stresses analysis of profiled axial compressor disc.
9
Dostęp do pełnego tekstu na zewnętrznej witrynie WWW
The article presents systems which record parameters of flight in modern aircraft F-16, which was delivered to Polish Airforce in 2006. These systems are responsible for the flight safety. Systems records basics parameters of plane and engine, as specific fuel consumption or height of flight, also provides video and audio recording, and aerial combat assistance. These systems record even failures of a braking system during landing. Thanks to modern technology, and devices like those described in this article, F-16 is one of the best fighters in the world.
PL
W artykule przedstawiono systemy rejestrujące parametry lotu w nowoczesnych samolotach F-16, które zostały dostarczone do polskich Sił Powietrznych w 2006 roku. Systemy te są odpowiedzialne za bezpieczeństwo lotów. System rejestruje podstawowe parametry samolotu i silnika, są to np. zużycie paliwa lub wysokość lotu. Systemy te zapewniają również nagrywanie wideo i dźwięku oraz zapewniają pilotowi wsparcie podczas walki powietrznej. Użyte w F-16 systemy rejestracji i przechowania danych są zdolne rejestrować nawet awarie układu hamulcowego podczas lądowania. Dzięki nowoczesnej technologii i urządzeniom opisanym w niniejszym artykule, F-16 jest jednym z najlepszych najlepszych samolotów bojowych na świecie.
The article presents systems, which record parameters of flight in modern aircraft F-16, which was delivered to Polish Airforce in 2006. With the current level of technical development of the aviation industry, data acquisition systems are an important element of all aircrafts. These systems are responsible for the flight safety, allow reading and storing the most important flight parameters, and combined with digital control and safety systems allow to counteract dangerous situations, which especially can happen often in the case of military aircraft such as the F-16 due to their combat purpose. Systems records basics parameters of plane and engine, as specific fuel consumption or height of flight provides video and audio recording, and aerial combat assistance. These systems record even failures of a braking system during landing. Thanks to modern technology, and devices like those described in this article, F-16 is one of the best fighters in the world. The amount of data provided by analogue and digital sensors is so large that it requires the partitioning of parameters and use of several basic recorders of the entire system is the unit called DAU, or Data Acquisition Unit, which records the most important flight parameters, such as flight time, engine speed, or altitude.
The article describes emergency situations occurring in the propulsion system of an aircraft with the jet engine used in Poland on planes such as MiG-29 or F-16. The article also presents statistics of polish aircrafts damage over the years. Due to the technological progress of turbine engines used in fighter aircraft, the authors decided to discuss the issue of monitoring emergency states in this study. In particular, efforts have been made to ensure that damage to the aircraft engine can be prevented by monitoring its operation with the equipment available on the aircraft. Counteracting phenomena that occur in the jet engine can lead to permanent damage; can lead to an increase in the safety of the pilot and the local population, but also to a reduction of costs. The authors also decided to se the threats that occur during take-off and landing, and the flight when they land outside the plane. Jet engines are almost reliable and most common cause of engine damages as the analysis shows are foreign bodies, particularly dangerous for a turbine engine on or near the runway, as well as birds, which provides to mechanical damage of engine. Securing the airport against foreign objects on the runway is one of the most important tasks of ground staff.
Nowadays, air transport is in an intense development phase. In order to optimize air communication and make it even more economical and environmentally friendly, attempts are made to undertake such activities as, e.g., SESAR project, which aims to develop and implement a modern ATM system. One of the parts of this project is the research on minimizing fuel consumption and emissions of pollutants in the engine exhausts. In the paper there is therefore presented the methodology for determining emission of those pollutants for the longest stage of the flight - the cruise phase. First, the value of the thrust required for the flight of an exemplary aircraft was deter-mined, and then the values of the engines trust and specific fuel consumption were computed. Additionally, it was necessary to determine the Emission Indexes (EI) of CO, NOx, HC and CO2 for the cruise phase, based on known such indexes for the LTO. Total emissions of these pollutants for the mission adopted to conduct research - a 1000 km long cruise - were determined. These emissions were computed for the exemplary aircraft per one kilometre, as well as per one hour of flight for various cruising altitudes and flight speeds.
The paper presents gas-dynamic calculations of a GTM 120 miniature turbine jet engine. The engine performance parameters have been determined and then validated with theory contained in literature as well as the results of research carried out on a laboratory test stand.
Among the most important problems currently faced by air transport, we can distinguish the adverse impact of aircrafts on the natural environment, as well as the rising costs of transport. One of the possibilities to improve this situation is better adjustment of aircraft characteristics to the performed transport tasks, taking into account all the requirements and limitations that exist in air traffic and the adverse impact of air transport on the natural environment. It is reflected in the research tasks conducted under the SESAR program. The aspiration to minimize the adverse impact of aircrafts on the environment is executed, among others, through determining such trajectories that are characterized by minimal fuel consumption or minimal emission of harmful substances in the engines exhausts. These goals are corresponding with the research conducted and described in the paper. The main aim of the work was to analyse the impact of wind speed and direction on the emission of harmful substances of a jet aircraft performing a flight on a given route. For research purposes, the route between two Polish cities Gdansk and Rzeszow was considered. The distance between the two airports was divided into sections for which wind direction and strength were determined (read from the windy.com website). Next, the aircraft performance was determined and the fuel consumption and the amount of harmful compounds (CO2, NOx, CO and HC), emitted in the engines exhausts were determined for the route from Gdansk to Rzeszow (under favourable wind conditions) and on the return route - from Rzeszow to Gdansk (under unfavourable wind conditions). For comparative purposes, emission of these substances for windless conditions was also determined. The results are presented in tables and depicted in the graph, as well as discussed in the conclusions of the paper.
Air transport is the youngest and most dynamically developing branch of transport. Growth in demand for air transport, both passenger and freight, is caused by the competitiveness of this branch primarily in terms of time and transport safety. An increase in the volume of air traffic is associated with increased emissions, which is particularly important in the case of aircraft operations in the areas of airports. The main reason for the development of aircraft engines is the reduction of fuel consumption and exhaust emissions. Emission standards for aircraft engines certification marginally treat the issue of particulate matter emissions, which is associated with deterioration of visibility appearing as smog and contributes to lung and heart diseases. One of the solutions for limiting the negative impact of the aircraft on the environment is the use of alternative fuels. Production of biofuels in accordance with the principles of sustainable development, is an attractive alternative, especially because of the lack of space constraints of their production allows the geographical diversification of supply. The article presents the measurements results of jet engine GTM-120 exhaust emissions. The test engine was powered with Jet A-1 fuel with 50-percent addition of bioester. During the test concentration of carbon monoxide, hydrocarbons and particulate matter was measured. On the basis of the measurements, the effect of the use of biofuel on emissions was presented.
PL
Transport lotniczy jest najmłodszą i najbardziej dynamicznie rozwijająca się gałęzią transportu. Wzrost zapotrzebowania na przewozy drogą lotniczą, zarówno pasażerskie i towarowe wynika głównie z krótkiego czasu transportu oraz bezpieczeństwa. Wzrost wolumenu transportowego związany jest ze wzrostem emisji związków szkodliwych spalin, co jest szczególnie istotne w kontekście emisji na terenie lotnisk oraz obszarach do nich przyległych. Głównym celem rozwoju konstrukcji silników lotniczych jest zmniejszenie zużycia paliwa i redukcja emisji związków toksycznych. Procedury certyfikacyjne dla silników odrzutowych marginalnie traktują zagadnienie cząstek stałych, które są powodem pogorszenia widzialności oraz chorób płuc i serca. Jednym z rozwiązań ograniczających wpływ transportu lotniczego na środowisko jest stosowanie paliw alternatywnych. W artykule przedstawiono wyniki pomiarów emisji związków szkodliwych silnia odrzutowego GTM-120. Badany silni zasilany był paliwem Jet A-1 oraz mieszanką nafty lotniczej z biopaliwem. Podczas badań zmierzono wartości stężenia tlenku węgla, węglowodorów oraz cząstek stałych. Na podstawie przeprowadzonych badań przedstawiono wpływ zastosowania biopaliwa na emisję związków szkodliwych.
16
Dostęp do pełnego tekstu na zewnętrznej witrynie WWW
Przedstawiono analizę wytrzymałościową trzech wariantów zamka trapezowego, których końcowa geometria powstała z wykorzystaniem modułu optymalizacji systemu ANSYS. Wprowadzono parametryzację geometrii stopki i wieńca tarczy, wykonano analizę porównawczą wytypowanych geometrii pod względem wytrzymałościowym. Zaprezentowano wyniki prób zastępczych modeli odwzorowujących połączenie zamkowe łopatki z wieńcem tarczy, do badań wykorzystano system cyfrowej korelacji obrazu.
EN
Presented is the strength analysis of three variants of the compressor’s jet engine blade joint whose final geometry was created using the ANSYS optimization module. Parameterization of the blade foot and rim geometry has been introduced and a comparative analysis of the selected geometry in terms of strength has been performed. In addition, results from the experimental analysis of the substitute models of blade joint with using the digital image correlation system were presented.
Micro scale gas turbine engines are low cost engines. They share their compressor impeller with automotive turbochargers. An identified design condition for the selected impeller is a critical stage of the design process. This process is had difficulties due the large number of manufacturers that provide OEM parts. It is common practice that one OEM part number provides the same impeller at different design revision. In general, parts are interchangeable but in detail, they differ slightly in terms of dimensions and performance. To avoid under predict or over predict inputs data, it is important to check the design parameters with as many methods as possible. In practice, the designer could rely on analytical methods, which are straightforward limited to the applied design. When shared its (compressor operation) it is recommended additional information be provided by computational fluid dynamics that produces a three-dimensional look into the predesign. That allows avoidance of future design failure and reduces both design time and prototype manufacturing costs.
The design a micro gas turbine engine is a process that requires analysis of a number of parameters. The initial stage requires consideration of more than 40 parameters [3]. The whole analysis can be made with analytical tools. However, these kinds of tools are limited to preliminary designs. After 1D-calculations and the establishment of the first CAD model, it is recommended to identify the sensitivity of the design. With a modern numerical environment such as ANSYS CFX, it is possible to predict a trend that gives the designer a 3D feedback about the initial design behaviour. For presented centrifugal compressor case, the selected parameters are vaneless diffuser space, design angle and number of stator blades. For qualitative evaluation – important results that influence design are mass flow rate, total pressure and isentropic efficiency. These results are important to turbojet engine performance and efficiency. All chosen parameters respond to given criteria. Validation and verification is still required due numerical errors that are included in CFD modelling. The advantage of 3D prediction is the possibility to eliminate gross errors before parts are sent into production.
The main purpose of this article was to point out causes of reduced fuel consumption in aircraft jet engine when aircraft is in ground effect influence. Wing in ground effect occurs in the direct proximity of ground. The paper presents wing in ground effect description, with the numerical analysis of NACA M8 airfoil in three different conditions of flight. Numerical analysis was conduct in Ansys Fluent 17.2 software. The paper shows results of simulations which describes wing in ground effect influence on NACA M8 airfoil with two cases of jet engine exhaust gasses usage, first with exhaust gasses stream turns on upper airfoil surface, and second with exhaust gasses stream turns under lower airfoil surface. Results allow to define characteristics of NACA M8 airfoil in the influence of wing in ground effect which are lift coefficient, drag coefficient, drop of fuel consumption usage by the jet engine when lift force remains still in the wing in ground effect. The paper shows that in the wing in ground effect aircraft energy usage for flight in ground effect is smaller than for free air flight.
The diagnostic testing of internal combustion engine can be made by using working processes and methods which take advantage of leftover processes. Working processes give information about general condition of internal combustion engine. Leftover processes give information about condition of particular subassemblies and kinematic couples; hence they are used as autonomous processes or as processes supporting other diagnostic methods. Methods based on analysis of vibrations and noise changes to determine technical condition of object are named as vibroacoustic diagnostics. In papers about vibroacoustic diagnostics of engine, problems connected with difficulty to select test point and to define diagnostic parameters containing essential information about engine’s condition, are most often omitted. Selection of engine’s working parameters and conditions of taking measurements or recording vibration signal are usually based on references, researcher’s experience or intuition. General assumptions about taking measurements of signal closest to its source are most often used. This paper presents a new approach to vibroacoustic diagnostics of jet engine. Selection of measurement points of vibration signals on the basis of tests stand results was suggested and perform a sensitivity analysis of measurement points on the engine support.
JavaScript jest wyłączony w Twojej przeglądarce internetowej. Włącz go, a następnie odśwież stronę, aby móc w pełni z niej korzystać.