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1
Kania, Henryk, et Mariola Saternus. « Evaluation and Current State of Primary and Secondary Zinc Production—A Review ». Applied Sciences 13, no 3 (3 février 2023) : 2003. http://dx.doi.org/10.3390/app13032003.
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This article presents the history of zinc, its production and demand. The quantity of zinc production, both primary zinc from ores and concentrates, and secondary zinc from scrap and zinc-rich waste, was discussed. A comprehensive economic analysis covers zinc prices in the years 1960–2021. The basic methods of obtaining zinc from ores, including pyrometallurgical (Imperial Smelting Process ISP, Kivcet, Ausmelt) and hydrometallurgical (roasting–leaching–electrowinning RLE, atmospheric direct leaching ADL, Engitec Zinc Extraction EZINEX, zinc pressure leach) and their short characteristics, are presented. The global zinc market and the main areas of its application were analyzed. Technologies used for the recovery of zinc from scrap are discussed along with their characteristics. Galvanized steel is the main source of secondary zinc, both in the galvanizing process and in the remelting of galvanized steel. It can be easily recycled with other scrap steel in the electric arc furnace (EAF) for steel production. Currently, with high volatility in the price of zinc, as well as its natural resources in the earth’s crust, recycling is an important activity, despite the fact that zinc concentrates have a relatively constant chemical composition, while the resulting zinc waste contains zinc in varying amounts.
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Lister, A. « II — A. Lister ». Journal of Navigation 38, no 3 (septembre 1985) : 431–35. http://dx.doi.org/10.1017/s0373463300032793.
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Several years ago, when Airbus Industrie launched their twin-engined A 300 Airbus, it became apparent that a new generation of long-range aircraft was about to add a different facet to the shape of international air travel. The enormous power available from the big fan engines coming into use meant that adequate performance was available even when an engine failure meant the loss of half the installed thrust. Coupled to this was a standard of fuel economy and tank capacity which meant that the new aircraft were capable of operating over ranges far in excess of those previously attained by twin-engined aircraft.
3
Rubino, L., R. I. Crane, J. S. Shrimpton et C. Arcoumanis. « An electrostatic trap for control of ultrafine particle emissions from gasoline-engined vehicles ». Proceedings of the Institution of Mechanical Engineers, Part D : Journal of Automobile Engineering 219, no 4 (1 avril 2005) : 535–46. http://dx.doi.org/10.1243/095440705x6668.
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Health concerns over ultrafine (< 100 nm) particles in the urban atmosphere have focused attention on measurement and control of particle number as well as mass. Gasoline-engined as well as diesel-engined vehicles are likely to be within the scope of future particulate matter (PM) emission regulations. As a potential option for after-treatment of PM emissions from gasoline engines, the trapping performance of a catalysed wire-cylinder electrostatic trap has been investigated, first in a laboratory rig with simulated PM and then in the exhaust of a direct injection spark ignition engine. In the simulation experiments, the trap achieved capture efficiencies by total particle number exceeding 90 per cent at wire voltages of 7–10 kV, gas temperatures up to 400°C, and operating durations up to one hour, with no adverse effects from a catalyst coating on the collecting electrode. In the engine tests, at moderate speeds and loads, capture efficiency was 60–85 per cent in the homogeneous combustion mode and 50–60 per cent, of a much larger number of engine-out particles, in the stratified (overall-lean) mode. Gas residence time in the trap appeared to be a major factor in determining efficiency. The electrical power requirement and the effect on engine back-pressure were both minimal.
4
Wilde, G. L. « A New Approach to the Design of the Large Turbofan Power Plant ». Proceedings of the Institution of Mechanical Engineers, Part G : Journal of Aerospace Engineering 209, no 2 (avril 1995) : 85–104. http://dx.doi.org/10.1243/pime_proc_1995_209_277_02.
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The lower direct operating costs of the Big Twin subsonic transports encourage the building of ever larger turbofan engines installed on the wings. The steadily improving reliability of the turbofans and the good safety statistics of twin-engined aircraft over many years encourages this trend. Fuel economy is still the dominant factor in determining the design layout of turbofan engines. It requires the combination of the highest possible thermal efficiency of the gas generator core of the engine with optimum propulsion efficiency of the power plant as a whole in cruise flight, allowing for engine nacelle drag and nacelle to wing interference drag. High thermal efficiency and high propulsion efficiency together, lead to relatively small volume flow rate gas generators and high volume flow rate propulsion fans. The resulting geometrical mismatch between the compressors and turbines of the principal turbomachinery components within the engine, introduces losses that penalize the performance gains expected from theoretical considerations of thermodynamics cycle and component efficiencies alone. The paper presents two possible turbofan design layouts intended to overcome the limitation of current turbofan power plant designs. The aim is to design a power plant with the highest thrust per unit frontal area combined with the highest air miles per gallon in cruise flight.
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Salama, Ramiz, et Mohamed ElSayed. « Basic elements and characteristics of game engine ». Global Journal of Computer Sciences : Theory and Research 8, no 3 (29 décembre 2018) : 126–31. http://dx.doi.org/10.18844/gjcs.v8i3.4023.
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Contemporary game engines are invaluable tools for game development. There are many engines available, each of them which excel in certain features. Game Engines is a continuous series that helps us to make and design beautiful games in the simplest and least resource way. Game drives support a wide variety of play platforms that can translate the game into a game that can be played on different platforms such as PlayStation, PC, Xbox, Android, IOS, Nintendo and others. There is a wide range of game engines that suit every programmer and designed to work on Unity Game Engine, Unreal Game Engine and Construct Game Engine. In the research paper, we discuss the basic elements of the game engine and how to make the most useful option among Game Engines depending on your different needs and needs of your game. Keywords: Game engine, game engine element, basics of game engine.
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Ke, Zhenying, Yang Xu et Zihao Guo. « Analysis of the social impact of heat engine and its future application ». IOP Conference Series : Earth and Environmental Science 1011, no 1 (1 avril 2022) : 012007. http://dx.doi.org/10.1088/1755-1315/1011/1/012007.
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Abstract This paper aims to evaluate the social impact of the heat engine and analyze the application of heat engines in the future. This paper starts with some background information on heat engines and the challenges of gas pollution and gas shortage. The concepts of efficiency and environmental friendliness of the heat engine are widely discussed, which speeds up the development of several kinds of heat engines. We discuss the application of heat engines in different industries from three main aspects: agriculture, marine engine, and aviation. They improve our daily life and provide the required energy to the community. Thermoacoustic Heat Engine (TAHE), Liquid Air Cycle Engines (LACE), and a new class of Heat engine without the expulsion of reaction mass are introduced in this paper. Furthermore, the article will cover some futures. One is artificial intelligence, and another one is about biofuel, which helps heat engines to have higher efficiency and less pollution, and also how heat engines are involved in the next decade.
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Biernat, Krzysztof, Izabela Samson-Bręk, Zdzisław Chłopek, Marlena Owczuk et Anna Matuszewska. « Assessment of the Environmental Impact of Using Methane Fuels to Supply Internal Combustion Engines ». Energies 14, no 11 (7 juin 2021) : 3356. http://dx.doi.org/10.3390/en14113356.
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This research paper studied the environmental impact of using methane fuels for supplying internal combustion engines. Methane fuel types and the methods of their use in internal combustion engines were systematized. The knowledge regarding the environmental impact of using methane fuels for supplying internal combustion engines was analyzed. The authors studied the properties of various internal combustion engines used for different applications (specialized engines of power generators—Liebherr G9512 and MAN E3262 LE212, powered by biogas, engine for road and off-road vehicles—Cummins 6C8.3, in self-ignition, original version powered by diesel fuel, and its modified version—a spark-ignition engine powered by methane fuel) under various operating conditions in approval tests. The sensitivity of the engine properties, especially pollutant emissions, to its operating states were studied. In the case of a Cummins 6C8.3 modified engine, a significant reduction in the pollutant emission owing to the use of methane fuel, relative to the original self-ignition engine, was found. The emission of carbon oxide decreased by approximately 30%, hydrocarbons by approximately 70% and nitrogen oxide by approximately 50%, as well as a particulate matter emission was also eliminated. Specific brake emission of carbon oxide is the most sensitive to the operating states of the engine: 0.324 for a self-ignition engine and 0.264 for a spark-ignition engine, with the least sensitive being specific brake emission of nitrogen oxide: 0.121 for a self-ignition engine and 0.097 for a spark-ignition engine. The specific brake emission of carbon monoxide and hydrocarbons for stationary engines was higher in comparison with both versions of Cummins 6C8.3 engine. However, the emission of nitrogen oxide for stationary engines was lower than for Cummins engines.
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MITIANIEC, Władyslaw, et Konrad BUCZEK. « Modification of four-stroke engine for operation in two-stroke cycle for automotive application ». Combustion Engines 162, no 3 (1 août 2015) : 3–12. http://dx.doi.org/10.19206/ce-116860.
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The main disadvantages of two-stroke engines such a big fuel consumption and big emission of hydrocarbons or carbon monoxide can be reduced by new proposal of design of two stroke engine based on four stroke engines. The paper describes the operation of high supercharged spark ignition overhead poppet valve two-stroke engine, which enables to achieve higher total efficiency and exhaust gas emission comparable to four-stroke engines. The work of such engines is possible by proper choice of valve timings, geometrical parameters of inlet and outlet ducts and charge pressure. The engine has to be equipped with direct fuel injection system enabling lower emission of pollutants. The work is based on theoretical considerations and engine parameters are determined on the simulation process by use GT-Power program and CFD program for different engine configurations. The initial results included in the paper show influence of valve timing on engine work parameters and predicted exhaust gas emission. The simulation results show that the nitrogen oxides are considerably reduced in comparison to four-stroke engines because of higher internal exhaust gas recirculation. The innovation of this proposal is applying of variable valve timing with turbocharging system in the two-stroke engine and obtaining a significant downsizing effect. The conclusions shows the possibilities of applying two-stroke poppet valve engine as a power unit for transportation means with higher total efficiency than traditional engines with possible change of engine operation in two modes: two- and four stroke cycles. The main disadvantages of two-stroke engines such a big fuel consumption and big emission of hydrocarbons or carbon monoxide can be reduced by new proposal of design of two stroke engine based on four stroke engines. The paper describes the operation of high supercharged spark ignition overhead poppet valve two-stroke engine, which enables to achieve higher total efficiency and exhaust gas emission comparable to four-stroke engines. The work of such engines is possible by proper choice of valve timings, geometrical parameters of inlet and outlet ducts and charge pressure. The engine has to be equipped with direct fuel injection system enabling lower emission of pollutants. The work is based on theoretical considerations and engine parameters are determined on the simulation process by use GT-Power program and CFD program for different engine configurations. The initial results included in the paper show influence of valve timing on engine work parameters and predicted exhaust gas emission. The simulation results show that the nitrogen oxides are considerably reduced in comparison to four-stroke engines because of higher internal exhaust gas recirculation. The innovation of this proposal is applying of variable valve timing with turbocharging system in the two-stroke engine and obtaining a significant downsizing effect. The conclusions shows the possibilities of applying two-stroke poppet valve engine as a power unit for transportation means with higher total efficiency than traditional engines with possible change of engine operation in two modes: two- and four stroke cycles.
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Rabeta, Bismil, Mohammad A.F Ulhaq, Aswan Tajuddin et Agus Sugiharto. « Simulasi Graphical User Interface Analisis Termodinamika Mesin Turboprop Menggunakan Perangkat Lunak Matlab R2020a ». Jurnal Teknologi Kedirgantaraan 6, no 2 (1 septembre 2021) : 31–50. http://dx.doi.org/10.35894/jtk.v6i2.44.
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A turboprop engine is a hybrid engine that delivers thrust or jet thrust and also drives the propeller. This is basically similar to a turbojet except the turbine works through the main shaft which is connected to the reduction gear to rotate the propeller in front of the engine. This research was conducted to determine the development of engine performance in thermodynamic analysis so as to know the value of each parameter on a engine that has been developing for 20 to 50 years with different engine manufacturing. So that in this study a comparison of the thermodynamic analysis of the TPE-331, PT6A-42 and H85-200 engines was carried out. In the TPE331-10, PT6A-42, and H85-200 turboprop engines the value of fuel to air ratio and shaft work increases with increasing altitude while compressor work, fuel flow rate, shaft power, propeller thrust, jet thrust, total thrust, equivalent engine power and ESFC decrease with increasing altitude. Furthermore, the turbine's working value is relatively stable as the altitude increases. After that, the value of compressor work and turbine work on the PT6A-42 engine was greater than that of the TPE331-10, and H85-200 engines. However, the value of the fuel to air ratio, fuel flow rate, shaft power, jet thrust, equivalent engine power and ESFC on the H85-200 engine was greater than the TPE331-10 and PT6A engines. Furthermore, at sea level, the value of the axle, propeller thrust, and total thrust on the H85-200 engine is greater than that of the TPE331-10 and PT6A-42 engines but at an altitude of 25,000 ft, the PT6A-4 engine has a greater value than that of the TPE331-10 and PT6A-42 engines. TPE331-10, and H85-200 engines.
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Shokrollahihassanbarough, Farzad, Ali Alqahtani et Mirosław Wyszynski. « Thermodynamic simulation comparison of opposed two-stroke and conventional four-stroke engines ». Combustion Engines 162, no 3 (1 août 2015) : 78–84. http://dx.doi.org/10.19206/ce-116867.
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Today’s technology leveraging allows OP2S (Opposed Piston 2-Stroke) engine to be considered as an alternative for the conventional four-stroke (4S) engines as mechanical drive in various applications, mainly in transportation. In general, OP2S engines are suited to compete with conventional 4-stroke engines where power-to-weight ratio, power-to-bulk volume ratio and fuel efficiency are requirements. This paper does present a brief advent, as well as the renaissance of OP2S engines and the novel technologies which have been used in the new approach. Also precise thermodynamic benefits have been considered, to demonstrate the fundamental efficiency advantage of OP2S engines. Hence, simulations of two different engine configurations have been taken into consideration: a one-cylinder opposed piston engine and two-cylinder conventional piston four-stroke engine. In pursuance of fulfilling this goal, the engines have been simulated in AVL Boost™ platform which is one of the most accurate Virtual Engine Tools, to predict engine performance such as combustion optimization, emission and fuel consumption. To minimize the potential differences of friction losses, the bore and stroke per cylinder are taken as constant. The closed-cycle performance of the engine configurations is compared using a custom analysis tool that allows the sources of thermal efficiency differences to be identified and quantified. As a result, brake thermal efficiency, power and torque of OP2S engine have been improved compared to conventional engines while emission concern has been alleviated.
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Minh, Thang Nguyen, Hieu Pham Minh et Vinh Nguyen Duy. « A review of internal combustion engines powered by renewable energy based on ethanol fuel and HCCI technology ». AIMS Energy 10, no 5 (2022) : 1005–25. http://dx.doi.org/10.3934/energy.20220046.
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<abstract> <p>In general, as compared to conventional combustion engines, the homogeneous charge compression ignition (HCCI) engine offers better fuel efficiency, NOx, and particulate matter emissions. The HCCI engine, on the other hand, is not connected to the spark plugs or the fuel injection system. This implies that the auto-ignition time and following combustion phase of the HCCI engine are not controlled directly. The HCCI engine will be confined to a short working range due to the cold start, high-pressure rate, combustion noise, and even knocking combustion. Biofuel innovation, such as ethanol-powered HCCI engines, has a lot of promise in today's car industry. As a result, efforts must be made to improve the distinctive characteristics of the engine by turning the engine settings to different ethanol mixtures. This study examines the aspects of ethanol-fueled HCCI engines utilizing homogenous charge preparation procedures. In addition, comparing HCCI engines to other advanced combustion engines revealed their increased importance and prospective consequences. Furthermore, the challenges of transitioning from conventional to HCCI engines are examined, along with potential answers for future upgrade approaches and control tactics.</p> </abstract>
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Minh, Thang Nguyen, Hieu Pham Minh et Vinh Nguyen Duy. « A review of internal combustion engines powered by renewable energy based on ethanol fuel and HCCI technology ». AIMS Energy 10, no 5 (2022) : 1005–25. http://dx.doi.org/10.3934/energy.2022046.
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<abstract> <p>In general, as compared to conventional combustion engines, the homogeneous charge compression ignition (HCCI) engine offers better fuel efficiency, NOx, and particulate matter emissions. The HCCI engine, on the other hand, is not connected to the spark plugs or the fuel injection system. This implies that the auto-ignition time and following combustion phase of the HCCI engine are not controlled directly. The HCCI engine will be confined to a short working range due to the cold start, high-pressure rate, combustion noise, and even knocking combustion. Biofuel innovation, such as ethanol-powered HCCI engines, has a lot of promise in today's car industry. As a result, efforts must be made to improve the distinctive characteristics of the engine by turning the engine settings to different ethanol mixtures. This study examines the aspects of ethanol-fueled HCCI engines utilizing homogenous charge preparation procedures. In addition, comparing HCCI engines to other advanced combustion engines revealed their increased importance and prospective consequences. Furthermore, the challenges of transitioning from conventional to HCCI engines are examined, along with potential answers for future upgrade approaches and control tactics.</p> </abstract>
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French, C. C. J. « Alternative Engines—Curiosities or Competitors ? » Proceedings of the Institution of Mechanical Engineers, Part A : Journal of Power Engineering 203, no 2 (mai 1989) : 79–96. http://dx.doi.org/10.1243/pime_proc_1989_203_012_02.
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This paper describes different types of engine used for transportation purposes. Some of the more interesting developments in spark ignition and diesel engines are outlined, but the paper is mainly a review of some of the alternative power plants that have been studied over the past 40 years. These include vapour cycle engines, free-piston engines, compound engines, Stirling engines, gas turbines, stratified charge engines, the catalytic engine, rotary engines and two-stroke spark ignition engines. The paper concludes by discussing possible future developments for some of these alternative engines.
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Тимошевський, Борис Георгійович, Олександр Сергійович Митрофанов, Андрій Станіславович Познанський et Аркадій Юрійович Проскурін. « АНАЛІЗ КОНСТРУКЦІЇ ТА ТЕХНОЛОГІЇ ВИГОТОВЛЕННЯ ПЕРСПЕКТИВНИХ РОТОРНО-ПОРШНЕВИХ ДВИГУНІВ ». Aerospace technic and technology, no 4 (28 août 2020) : 28–37. http://dx.doi.org/10.32620/aktt.2020.4.04.
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The article discusses the main directions of development of creating new modern and improving existing rotary piston engines. The need for a systematic analysis of existing similar engine designs is established to separate and systematize their advantages and disadvantages at the design stage. As an analysis of the design and manufacturing technology of the existing most promising rotary piston engines, turbocompressor-type circuits with a movable cylinder block is considered, the engines in which the combustion takes place outside the working cylinder, the drum-piston type with movable combustion chambers, rotary expanders, etc. It is established that the structure of the housing of rotary piston engines with an internal cylindrical surface, in which the rotor with working cylinders is located, allows the creation of economical and compact engines. This structure of the engines allows you to reduce vibration and make them safer to use. A comparison of the mechanisms of motion of existing rotary piston engines. Based on the analysis of existing schemes and the design of modern rotary piston engines, a sample of a new design 12 RPE-4.4/1.75 rotary piston engine is designed. The design and basic parameters of a new model of the 12 RPE-4.4/1.75 rotary piston engine with adjustable spool air distribution are presented. The engine has twelve evenly spaced cylinders, provides a balanced engine, and the ability to start at any position of the rotor. The design of the engine designed provides for a central control cam shaft, the rotation of which allows you to adjust the valve timing and engine operation due to the degree of filling of the cylinder in a fairly wide range. A feature of the design of the engine is also that the control cam allows you to change the direction of rotation of the central rotor. It was found that the design of the crank mechanism of the 12 RPE-4.4/1.75 engine is simple in structure and production technology, as well as more reliable compared to similar existing rotary piston engines.
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Ye, Zheng Mao, et Habib Mohamadian. « Simple Engine Exhaust Temperature Modeling and System Identification Based on Markov Chain Monte Carlo ». Applied Mechanics and Materials 598 (juillet 2014) : 224–28. http://dx.doi.org/10.4028/www.scientific.net/amm.598.224.
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Even though actual composition of engine exhaust gases varies across diverse types of engines, such as gasoline, diesel, gas turbine and natural gas engines, engine exhaust temperature is always a major factor with strong impact on emission levels and catalytic converting efficiency. For spark ignition engines, exhaust temperature depends on various engine parameters, such as engine speed, engine load, A/F ratio, intake air temperature, coolant temperature and spark timing, etc. Due to complexity, it is impossible to share a unique analytical model of engine exhaust temperature. Instead, it is mostly modeled as a complicated nonlinear system. The model complexity increases significantly however accuracy cannot be guaranteed. On the other hand, a simple linear model with accurate system identification could serve as a versatile alternative to represent the engine exhaust temperature, while engine parameters are subject to model identification to be adaptable across different types of engines. Combination of linear functions in terms of dominant engine parameters of engine speed and engine load is used for exhaust temperature modeling. To identify optimal parameters, Markov Chain Monte Carlo (MCMC) is applied. The discrete-time Markov chain is introduced where the stationary probability replaces posterior density in Monte Carlo integration for numerical integration. Compared with the high order nonlinear approaches, low computation cost is involved in the simplified model. Good agreement between the model prediction data and testing results is observed. The approach could be easily extended to other types of engines.
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Noh, Kichol, et Changhee Lee. « Development of an Ignition System and Assessment of Engine Performance and Exhaust Characteristics of a Marine Gas Engine ». Sustainability 13, no 8 (7 avril 2021) : 4097. http://dx.doi.org/10.3390/su13084097.
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In recent years, marine engine manufacturers have become increasingly interested in gas engines as an alternative to diesel engines to address rising crude oil prices and environmental regulations. In this study, a 1.6 MW dedicated gas engine was developed based on a diesel engine with bore 220, stroke 300. The developed gas engine had a precombustion chamber and exhibited excellent performance; the brake mean effective pressure was 2.1 MPa at 1000 rpm and NOx emissions were 50 ppm under 15% O2. In particular, it demonstrated excellent fuel economy with a thermal efficiency of 45%, and its carbon dioxide emissions were ~75% of the conventional diesel engines, thus demonstrating greenhouse gas reduction. These results indicate that suitably developed gas engines can provide a low-cost and energy-efficient alternative to diesel engines.
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Fryer, Chris L. « Compact Remnant Constraints on the Core-Collapse Engine ». Proceedings of the International Astronomical Union 16, S363 (juin 2020) : 19–32. http://dx.doi.org/10.1017/s1743921322000527.
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AbstractThe convection-enhanced neutrino-driven supernova engine’s success in explaining a myriad of supernova properties has set it as the standard engine behind supernova. However, due to the success of rotationally-powered engines in explaining astrophysical transients like gamma-ray bursts, these engines have been revived as possible drivers of normal supernovae, competing with this standard engine. In this paper, these competing engines, and the constraints placed by compact remnant observations on these engines, are reviewed. We find that, with these constraints, such rotationally-powered engines can explain less than 1% of the current supernova remnants. In addition, we find that the remnant mass distribution can be used to constrain properties of the convection-enhanced neutrino-driven engine, helping astronomers understand the nature of convection in this engine.
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Duan, Chen, Shui Ming Shu, Guo Zhong Ding et Ji Wei Yan. « Preliminary Design and Adiabatic Analysis of a 3kW Free Piston Stirling Engine ». Applied Mechanics and Materials 325-326 (juin 2013) : 277–82. http://dx.doi.org/10.4028/www.scientific.net/amm.325-326.277.
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In recent years, as one kind of Stirling engines, free piston Stirling engines are attracting world attention. Free piston Stirling engines could be applied to the solar dish system, micro-CHP system and so on. The development of a free piston Stirling engine is discussed in this paper. The ideal adiabatic model is used in the preliminary design of the free piston Stirling engine. The key parameters of the designed engine and the thermodynamic analysis are described in detail. Then the performance of the engine is obtained.
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Ferral-Smith, Hayden, Georgia Giannakakis, Joshua Wilson et Joshua Taylor. « Factors Influencing the Thermodynamic Efficiency of Stirling Engines ». PAM Review Energy Science & ; Technology 4 (5 juin 2017) : 17–29. http://dx.doi.org/10.5130/pamr.v4i0.1459.
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This meta-study examines the factors which contribute to Stirling engine efficiency. Working fluids should have high specific heat capacity, low viscosity and low density making noble gases the most suitable. Each different working fluid has its own optimum power output at varying pressures and temperatures. The best being Helium at 4.14 MPa and 922K. Dead volume also affects the power output of Stirling engines. Theoretical engines with zero dead volume are ideal but dead volume can occupy over 50% of the engine. Engine configuration also impacts on the efficiency of a Stirling engine. The layout of pistons and cylinders about each other can also have drastic effects on these efficiencies. Currently the most effective engine layout is the ‘gamma’ configuration, which measures 30%-32% efficient. Future research is required to produce a more efficient Stirling engines, based on the factors considered above to determine the viability of these engines as a replacement for coal and fossil fuel powered combustion engines.
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Brzeski, L., et Z. Kazimierski. « A New Concept of Externally Heated Engine—Comparisons with the Stirling Engine ». Proceedings of the Institution of Mechanical Engineers, Part A : Journal of Power and Energy 210, no 5 (octobre 1996) : 363–71. http://dx.doi.org/10.1243/pime_proc_1996_210_060_02.
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This paper presents a new concept of the externally heated valve (EHV) engine. Air can be used as a working medium in the closed cycle of this engine. Heat delivered to the working air can come from a combustion chamber or another heat generator of an arbitrary type. The engine construction and the thermodynamic cycle performed by it are original and entirely different from the well-known Stirling engine. The main disadvantage of the Stirling engine is its low power density, that is the low power obtained per litre of the engine cylinder volume. In the case of the engine presented here it is possible to achieve power density and efficiency similar to those typical of advanced internal combustion engines. Comparisons between the power of the Stirling engine and the power of the new engine have been performed for the same engine capacity, rotational frequency and maximum and minimum temperatures of the cycle. At the same minimum pressure of the working gas in both engines, the power of the EHV engine is several times higher than that of the Stirling engine, while, on the other hand, at the same maximum pressure of the working gas in both engines, the power of the EHV engine is 20 per cent higher than that of the Stirling engine power. The efficiencies of both engines do not differ significantly from each other.
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A., Armaan, et Srinivas G. « In Tune with Times : Recent Developments in Theoretical, Experimental and Numerical techniques of Aircraft Engines ». International Journal of Engineering & ; Technology 7, no 2 (23 mai 2018) : 805. http://dx.doi.org/10.14419/ijet.v7i2.10910.
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Today the aircraft engine designing and development work is increasing drastically. Especially aircraft engines play a vital role in order to decide the aircrafts speed and its performance. Broadly turbojet, turboprop, turbo shaft and turbofan engines comes under the category of air breathing engines. Every engine has its own purpose and application. But modern aircrafts require much more advancements. Designing a new aircraft engine has been a really challenging task to the researchers. But giving a complete holistic view of aircraft engines and research gap would definitely help a lot to the new designers. Once identified the drawbacks of engine performance can be corrected in the future. For any new design of aircraft engine researchers are suggested to take Theoretical, Experimental and Numerical approaches. Therefore present paper makes an effort to review complete recent Theoretical, Experimental and Numerical approaches which are followed till date. Under all the three approaches all the air breathing engines have been clearly explained and solicited. The effort is to identify the gaps between different approaches which are hampering the process of engine development. The paper also gives the research gaps that need to be incorporated for effective performance enhancement of the aircraft engines for aeromechanical features.
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OPALIŃSKI, Marcin, Andrzej TEODORCZYK et Jakub KALKE. « The closed-cycle model numerical analysis of the impact of crank mechanism design on engine efficiency ». Combustion Engines 168, no 1 (1 février 2017) : 153–60. http://dx.doi.org/10.19206/ce-2017-125.
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The research presents a review and comparison of different engine constructions. Investigated engines included crankshaft engines, barrel engine, opposed-piston engines and theoretical models to present possible variations of piston motion curves. The work comprises also detailed description of a numerical piston engine model which was created to determine the impact of the cycle parameters including described different piston motion curves on the engine efficiency. Developed model was equipped with Wiebe function to reflect a heat release during combustion event and Woschini’s correlation to simulate heat transfer between the gas and engine components.Various scenarios of selected engine constructions and different working conditions have been simulated and compared. Based on the results it was possible to determine the impact of different piston motion curves on the engine cycle process and present potential efficiency benefits.
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Chen, G., P. L. Flynn, S. M. Gallagher et E. R. Dillen. « Development of the Low-Emission GE-7FDL High-Power Medium-Speed Locomotive Diesel Engine ». Journal of Engineering for Gas Turbines and Power 125, no 2 (1 avril 2003) : 505–12. http://dx.doi.org/10.1115/1.1563241.
Texte intégralRésumé :
This paper summarizes the technical development of the low-emission GE-7FDL series locomotive diesel engine. The development focused on reducing the engine exhaust NOx emission significantly while reducing and curbing other visible and nonvisible emissions with minimal adverse impact on the engine fuel efficiency and minimal changes to the engine system and components. Concepts were analyzed, and were investigated using a single-cylinder 7FDL research engine. A low-emission 16-cylinder 7FDL engine and a GE locomotive prototype were built and tested for performance demonstration, function evaluation, and design optimization. The GE low-emission 7FDL engines and locomotives have been in production. The newly developed low-emission locomotive engine meets the EPA Tier-0 levels without fuel efficiency penalty. This was accomplished with minimal changes to the engine system and components. The desired engine reliability performance is retained. The engines are interchangeable with the preceding 7FDL baseline models, and the upgrade of the existing baseline engines to the low-emission version is facilitated.
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Teng, Fei. « A brief introduction to the typical fuels for SI engine and its future projections ». Journal of Physics : Conference Series 2419, no 1 (1 janvier 2023) : 012067. http://dx.doi.org/10.1088/1742-6596/2419/1/012067.
Texte intégralRésumé :
Abstract Spark Ignition (SI) engine has been widely used and developed in the engineering field due to its high performance and safety. At present, the SI engine has received extensive attention from many experts and scholars and has become a research hotspot and focus in the field of heat engines. This paper studies the development status of SI engines from multiple perspectives. The research status of performance and pollutant emissions of commercial SI engines were analyzed by literature search. The numerical simulation principle and application method of the current SI engine were studied, and the emissions of the traditional engine and the SI engine were compared. It was found that the SI engine has irreplaceable advantages in terms of performance and emissions. In addition, this paper also looks forward to the development of the SI engine, and proposes that the future development of the SI engine should focus on improving its performance; the use of clean fuel is also an important research content of the SI engine.
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WINKLHOFER, Ernst, et Wolfgang HOPFNER. « Optical single cylinder engines in engine research and development ». Combustion Engines 152, no 1 (1 février 2013) : 71–78. http://dx.doi.org/10.19206/ce-117014.
Texte intégralRésumé :
We report on essential design elements of optically accessed research engines and describe selected examples of their applications in engine development. Whereas research topics most often address specific generic topics and are focused on comprehensive analysis of selected engine phenomena, the priority in using optical engines for engine development tasks is in providing data relevant for the operation of a normal multicylinder engine. In this latter case, optical engines are only used if their results have such high value that they justify the efforts required to achieve the outcome. Both, research and development applications, benefit from each other as they promote progress in optical engine technology as well as in application of new analysis techniques.
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Gettel, L. E., G. C. Perry, J. Boisvert et P. J. O’Sullivan. « Dual Fuel Engine Control Systems for Transportation Applications ». Journal of Engineering for Gas Turbines and Power 109, no 4 (1 octobre 1987) : 435–38. http://dx.doi.org/10.1115/1.3240059.
Texte intégralRésumé :
Microprocessor control systems have been developed for dual fuel diesel engines intended for transportation applications. Control system requirements for transportation engines are more demanding than for stationary engines, as the system must be able to cope with variable speed and load. Detailed fuel maps were determined for both normally aspirated and turbocharged diesel engines based on the criterion that the engine did not operate in the regimes where knock or incomplete combustion occurred. The control system was developed so that the engine would follow the detailed fuel map. The input variables to the control system are engine speed and load. Based on this, the system then controls the amount of natural gas and diesel fuel supplied to the engine. The performance of the system will be briefly summarized.
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Hanifuddin, Hanifuddin, Milda Fibria, Catur Y. Respatiningsih, Setyo Widodo et Maymuchar Maymuchar. « The Evaluation of Lubricants Performances in Light- and Heavy-Duty Diesel Engines in The Application of Biodiesel (B20). » Scientific Contributions Oil and Gas 43, no 2 (31 août 2020) : 81–90. http://dx.doi.org/10.29017/scog.43.2.523.
Texte intégralRésumé :
The use of biodiesel as fuel in light- and heavy-diesel engine vehicles in general will negatively affects the lubricant performance. the changes in lubricants properties during the use of B20 were investigated. Two type of vehicles engines were used, namely heavy duty and light duty diesel engines. The road test wascarried out until 40,000 km, while the lubricant was drained and analysed only for 10,000 km of distances. The laboratory test was conducted to observe both fresh and used lubricants. The results show that the biodiesel dilutions were less than 2% both in light- and heavy-duty diesel engines. The kinematic viscositiesof 4 samples of used lubricants in light-duty diesel engine were decreased in the ranges of 0.58 – 7.5%, while in heavy-duty diesel engines were 4.66-16.04% from the initial values. The decreasing of TBNs were less than 14% in light-duty diesel engine and fewer than 16% in heavy-duty diesel engine fuelled by biodiesel (B20). Meanwhile, the acidity of used engine oil was increased until 173% for light-duty diesel engine and 63% heavy-duty diesel engine compare to the initial values. The results show that the metal additives decreased while wear metal increased. According to this study, the increasing of wear metal (copper) in the used lubricants were less than 23% in light-duty diesel engine and lower than 26% in heavy-duty diesel engine fuelled by biodiesel (B20). Meanwhile, the lead contents of used engine oil were increased to 3.2 ppm in heavy-duty diesel engine and was not detected in light-duty diesel engine. After all, this work found that the lubricants exhibit good performances in the light- and heavy-duty diesel engines fuelled by B20. The changes of some critical properties were still in the acceptable values regarding to the specification as required in the SNI-7069-5 (2021).
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Salama, Ramiz, et Mohamed Elsayed. « A live comparison between Unity and Unreal game engines ». Global Journal of Information Technology : Emerging Technologies 11, no 1 (30 avril 2021) : 01–07. http://dx.doi.org/10.18844/gjit.v11i1.5288.
Texte intégralRésumé :
A game engine is an ongoing thread that helps us in making and designing beautiful games with the simplest methods and least resources. Game engines support a wide variety of playing platforms that can translate the game designed into a playable game in different platforms like PlayStation, PC, Xbox, Android, IOS and Nintendo. There is a wide variety of game engines that suits every programmer and designer working on engines such as Unity game engine, Unreal game engine and construct game engine. In order to make a game one has to learn how to code in one of these engines. From our results, Unity has everything you need to create games in one place. It has an integrated development framework that creates rich solutions and out-of-box functionality to make games. This paper recommends making a decision one has to look at, such as what platforms one wants to target and how one can plan on monetising their product. Keywords: Game engine, compare engine, Unity game, Unreal game, platforms.
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Kazienko, Damian, et Leszek Chybowski. « Instantaneous Rotational Speed Algorithm for Locating Malfunctions in Marine Diesel Engines ». Energies 13, no 6 (17 mars 2020) : 1396. http://dx.doi.org/10.3390/en13061396.
Texte intégralRésumé :
This article suggested broadening the standard methods for diagnosing the technical condition of diesel engines to include an analysis of the instantaneous rotational speed of compression combustion engines with the use of a novel algorithm. The authors revised the subject concerning the use of the analysis of instantaneous changes in the rotational speed of an engine when assessing its technical condition and the location of the malfunction. An algorithm and its practical implementation in a prototype diagnostic system called SpeedMA were presented. This article reported the test results of the prototype in the context of indicating the engine cylinder in which ignition failed to occur. Tests were carried out for two marine engines: a low-speed trunk engine directly driving the fixed-pitch propeller and a medium-speed trunk engine driving the alternator. For each case, an analysis was carried out for different engine loads and at individual cylinders in which combustion failed to occur. The experimental results showed an unambiguous relation between the combustion process of the examined engines and changes in the instantaneous rotational speed. The results also confirmed the usefulness of the proposed method and showed the correct operation of the presented diagnostic algorithm. The proposed diagnostic system could be used during the operation of engines running in real ship engine rooms.
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Cheng, Chin-Hsiang, et Duc-Thuan Phung. « Modeling of Thermal-Lag Engine with Validation by Experimental Data ». Energies 15, no 20 (18 octobre 2022) : 7688. http://dx.doi.org/10.3390/en15207688.
Texte intégralRésumé :
Thermal-lag engines are external combustion engines with a single moving piston. This feature leads to lower manufacturing and maintenance costs than traditional Stirling engines. Although the original concept of thermal-lag engines was invented roughly 35 years ago, the information on thermal-lag engines is still limited. Therefore, this study focuses on thermal-lag engine performance by developing a three-dimensional computational fluid dynamics (CFD) model. The grid independence check and the time step independence check are firstly performed to select the number of elements and size of the time step for simulation. The CFD model is then validated by the experimental data, which were collected by measuring an existing prototype engine. It has been found that the CFD predictions are well fitted to the experimental data over the range of engine speed from 200 to 1600 rpm at temperatures of 1173 or 1273 K. Furthermore, the CFD model predicts that the maximum engine power is 21.1 W while the prototype engine practically generates the highest power of 22.35 W at 1000 rpm and 1273 K. Finally, a further parametric study shows that crank radius, piston diameter, working gas mass, working gas species, and heating temperature significantly affect engine power.
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Nowak, Paweł. « INVESTIGATION OF THE PHYSICOCHEMICAL PROPERTIES OF A NEW SYNTHETIC LUBRICANT FOR PASSENGER CAR INTERNAL COMBUSTION ENGINES ». Tribologia 294, no 6 (12 avril 2021) : 45–55. http://dx.doi.org/10.5604/01.3001.0014.8335.
Texte intégralRésumé :
The subject of the article is a synthetic lubricant for the latest generation internal combustion engines, used especially in passenger cars, equipped with both spark ignition engines and compression ignition engines, which is used in particular in passenger cars operating in urban conditions, overcoming relatively short distances, and therefore working usually below the recommended operating temperature of the engine. The developed 5W30 oil maintains excellent rheological properties (fluidity) also before reaching the correct operating temperature of the engine, especially at negative temperatures, which results in lower oil pump resistance and reduced friction of key engine components, which ensures better engine working conditions and affects its service life.
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Ambrozik, Andrzej, Tomasz Ambrozik, Dariusz Kurczyński et Piotr Łagowski. « Comparative Assessment of CI Engine Response ». Transport and Communications 2, no 1 (2014) : 1–4. http://dx.doi.org/10.26552/tac.c.2014.1.1.
Texte intégralRésumé :
The response of the piston internal combustion engine provides an important indicator to assess the engine ability to adapt to constantly varying load conditions in its operation. It is the main criterion by which engines powering automotive vehicles are evaluated. It also affects road safety. The engine response depends on the profile of the curve that shows changes in the engine torque as a function of the crankshaft rotational speed. The paper presents a comparison of CI engines representing different generations with respect to constructional level. The engines that underwent comparison were equipped with the fuel system with a rotary injection pump and with Common Rail fuel system.
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Li, Chengqian, Yaodong Wang, Boru Jia, Zhiyuan Zhang et Anthony Roskilly. « Numerical Investigation on NOx Emission of a Hydrogen-Fuelled Dual-Cylinder Free-Piston Engine ». Applied Sciences 13, no 3 (20 janvier 2023) : 1410. http://dx.doi.org/10.3390/app13031410.
Texte intégralRésumé :
The free-piston engine is a type of none-crank engine that could be operated under variable compression ratio, and this provides it flexible fuel applicability and low engine emission potential. In this work, several 1-D engine models, including conventional gasoline engines, free-piston gasoline engines and free-piston hydrogen engines, have been established. Both engine performance and emission performance under engine speeds between 5–11 Hz and with different equivalent ratios have been simulated and compared. Results indicated that the free-piston engine has remarkable potential for NOx reduction, and the largest reduction is 57.37% at 6 Hz compared with a conventional gasoline engine. However, the figure of NOx from the hydrogen free-piston engine is slightly higher than that of the gasoline free-piston engine, and the difference increases with the increase of engine speed. In addition, several factors and their relationships related to hydrogen combustion in the free-piston engine have been investigated, and results show that the equivalent ratio φ=0.88 is a vital point that affects NOx production, and the ignition advance timing could also affect combustion duration, the highest in-cylinder temperature and NOx production to a large extent.
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Stelmasiak, Zdzisław. « Application of Alcohols to Dual - Fuel Feeding the Spark-Ignition and Self-Ignition Engines ». Polish Maritime Research 21, no 3 (28 octobre 2014) : 86–94. http://dx.doi.org/10.2478/pomr-2014-0034.
Texte intégralRésumé :
Abstract This paper concerns analysis of possible use of alcohols for the feeding of self - ignition and spark-ignition engines operating in a dual- fuel mode, i.e. simultaneously combusting alcohol and diesel oil or alcohol and petrol. Issues associated with the requirements for application of bio-fuels were presented with taking into account National Index Targets, bio-ethanol production methods and dynamics of its production worldwide and in Poland. Te considerations are illustrated by results of the tests on spark- ignition and self- ignition engines fed with two fuels: petrol and methanol or diesel oil and methanol, respectively. Te tests were carried out on a 1100 MPI Fiat four- cylinder engine with multi-point injection and a prototype collector fitted with additional injectors in each cylinder. Te other tested engine was a SW 680 six- cylinder direct- injection diesel engine. Influence of a methanol addition on basic operational parameters of the engines and exhaust gas toxicity were analyzed. Te tests showed a favourable influence of methanol on combustion process of traditional fuels and on some operational parameters of engines. An addition of methanol resulted in a distinct rise of total efficiency of both types of engines at maintained output parameters (maximum power and torque). In the same time a radical drop in content of hydrocarbons and nitrogen oxides in exhaust gas was observed at high shares of methanol in feeding dose of ZI (petrol) engine, and 2-3 fold lower smokiness in case of ZS (diesel) engine. Among unfavourable phenomena, a rather insignificant rise of CO and NOx content for ZI engine, and THC and NOx - for ZS engine, should be numbered. It requires to carry out further research on optimum control parameters of the engines. Conclusions drawn from this work may be used for implementation of bio-fuels to feeding the combustion engines.
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Knauder, Christoph, Hannes Allmaier, David E. Sander et Theodor Sams. « Investigations of the Friction Losses of Different Engine Concepts. Part 2 : Sub-Assembly Resolved Friction Loss Comparison of Three Engines ». Lubricants 7, no 12 (25 novembre 2019) : 105. http://dx.doi.org/10.3390/lubricants7120105.
Texte intégralRésumé :
In this work, friction loss investigations and comparisons of three different four-cylinder engines for passenger car applications are presented, using a recently developed combined approach. By merging extensive experimental with reliable and predictive journal bearing simulation results, a sub-assembly-resolved friction loss analysis of the piston group, crankshaft journal bearings and valve train is conducted for all three engines. The engines have been chosen individually based on their specific power output and crank train geometry. The measurement program covers a wide range of corresponding engine operation points (identical speed, load and thermal boundary conditions). In addition, the investigations are carried out for different engine media supply temperatures ranging from 70 ∘ C to 110 ∘ C for a comprehensive consideration of the friction losses at reduced lubricant viscosity. For reasons of comparability, all investigations conducted in this work have been carried out using the same modern SAE 5W30 lubricant. This is done to exclude influences from different lubricant properties which may have significant effects on the tribological behaviour of the engines’ sub-assemblies. While the diesel engine showed a friction reduction potential over the entire engine operation range when increasing the engine media supply temperatures, the gasoline engines showed a different behaviour. For the gasoline engines, disadvantages arise especially at low engine speeds. By using the developed combined approach, it was possible to assign mixed lubrication regimes at the valve train systems and at the piston groups.
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GĘCA, Michał, Zbigniew CZYŻ et Mariusz SUŁEK. « Diesel engine for aircraft propulsion system ». Combustion Engines 169, no 2 (1 mai 2017) : 7–13. http://dx.doi.org/10.19206/ce-2017-202.
Texte intégralRésumé :
Stricter requirements for power in engines and difficulties in fueling gasoline engines at the airport make aircraft engine manufac-turers design new engines capable of combusting fuel derived from JET-A1. New materials used in compression-ignition engines enable weight reduction, whereas the technologies of a Common Rail system, supercharging and 2-stroke working cycle enable us to increasethe power generated by an engine of a given displacement. The paper discusses the parameters of about 40 types of aircraft compression ignition engines. The parameters of these engines are compared to the spark-ignition Rotax 912 and the turboprop. The paper also shows trends in developing aircraft compression-ignition engines.
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Dunn, M. G., C. Padova, J. E. Moller et R. M. Adams. « Performance Deterioration of a Turbofan and a Turbojet Engine Upon Exposure to a Dust Environment ». Journal of Engineering for Gas Turbines and Power 109, no 3 (1 juillet 1987) : 336–43. http://dx.doi.org/10.1115/1.3240045.
Texte intégralRésumé :
Results are reported for a measurement program designed to investigate the performance deterioration of a TF33 turbofan and a J57 turbojet engine upon exposure to a dust-laden environment. Engine parameters were measured in order to facilitate the recognition of incipient engine difficulties. In addition, a successful effort was made to operate the engines satisfactorily when they were severely damaged. Two TF33 engines have been operated in the same dust mixture but under different operating conditions and a J57 engine was operated at the same conditions as one of the TF33 engines. The JS7 is the core engine of the TF33 with some differences that will be described in the paper. A description of the experimental technique, the operating experiences, photographs of the components taken from the J57 engine in a post-test teardown, and a discussion of the results are presented.
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PUŠKÁR, Michal, Matúš LAVČÁK, Marieta ŠOLTÉSOVÁ et Melichar KOPAS. « ANALYSIS OF ADVANCED TECHNOLOGY FOR COMBUSTION OF HOMOGENEOUS FUEL MIXTURE ». Scientific Journal of Silesian University of Technology. Series Transport 117 (1 décembre 2022) : 211–20. http://dx.doi.org/10.20858/sjsutst.2022.117.14.
Texte intégralRésumé :
The most serious problems to overcome for a successful operation of the HCCI engine are control of the combustion phase, limited operational range, cold start of engine and high noise level during engine operation. This study aims at describing the engine power output characteristics and emission characteristics of HCCI engines under different testing conditions and the various challenges associated with these engines. Furthermore, this study holds a potential guide for overcoming these challenges and improvement of the engine power output as well as the emission characteristics. Thus, it is possible to say, concerning the performed investigation work, that HCCI combustion can be applied in existing conventional engines after their modifications. The most significant result of the HCCI process application is the reduction of NOx emissions and soot emissions, keeping almost the same engine power output as the conventional combustion process.
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Nikolić, N., N. Crnogorac, J. Dorić, D. Feher et S. Galamboš. « A comparison of main bearings load of two-cylinder “V” and boxer motorcycle engines ». IOP Conference Series : Materials Science and Engineering 1271, no 1 (1 décembre 2022) : 012006. http://dx.doi.org/10.1088/1757-899x/1271/1/012006.
Texte intégralRésumé :
Abstract The paper deals with determining the load of the crankshaft main bearings in two-cylinder motorcycle engines. Two cylinder arrangements, used in two-cylinder motorcycle engines, are considered - the boxer-engine and V-engine. The aim of the research is to determine the influence of cylinder arrangement on the magnitude and circumferential distribution of the bearing load of the engines considered. For this purpose, models of a two-cylinder boxer engine and a corresponding V-engine crankshaft drives were developed using multibody dynamics simulation software. Previously, by using a one-dimensional gas analysis software the engine cycles were simulated in order to determine the cylinder pressure required to simulate piston dynamics. As a result of the dynamics simulations, bearing load diagrams of the boxer- and V-engine were obtained, which were then compared and analyzed.
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Clarke, J. M., et W. G. Berlinger. « A New Compression Ignition Engine Concept for High Power Density ». Journal of Engineering for Gas Turbines and Power 121, no 2 (1 avril 1999) : 211–17. http://dx.doi.org/10.1115/1.2817107.
Texte intégralRésumé :
A new compression ignition (CI) engine concept has been identified which greatly improves power density over conventional CI engines. This paper reviews the scaling laws as they apply to power density (power/crate volume) and derives a parameter reflecting the compactness of any engine design. The new concept is compared to existing engines on the basis of this parameter. Ideal cycle analysis of the multistage thermodynamic processes inherent in the new arrangement leads to the expectation that this engine will be more efficient than current engines. Real cycle simulations and concept design work have confirmed that efficiency can be at least as high as current engines while size is much reduced. Design and analysis are continuing in order to establish that the durability and low emissions will be competitive with modern CI engines.
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Pylypenko, O. V., O. O. Prokopchuk, S. I. Dolgopolov, O. D. Nikolayev, N. V. Khoriak, V. Yu Pysarenko, I. D. Bashliy et S. V. Polskykh. « Mathematical modelling of start-up transients at clustered propulsion system with POGO-suppressors for CYCLON-4M launch vehicle ». Kosmìčna nauka ì tehnologìâ 27, no 6 (2021) : 3–15. http://dx.doi.org/10.15407/knit2021.06.003.
Texte intégralRésumé :
Liquid-propellant rocket propulsion systems of the first stages of launch vehicles of medium, heavy, and super-heavy class usually include POGO-suppressors, which are one of the most widely used methods to eliminate launch vehicle longitudinal structural vibrations (POGO phenomena). However, until now, the theoretical studies and analysis of the effect of the POGO-suppressors’ installation in the feedlines of main liquid rocket engines on transient processes in systems during rocket engine starting have not been carried out due to the complexity of such analysis and the lack, first of all, reliable nonlinear models of cavitation phenomena in rocket engine pumps. A mathematical model for the start-up of a clustered rocket propulsion of the Cyclone-4M launch vehicle has been developed that takes into account the low-frequency dynamics of the POGO-suppressors and the asynchronous start-up timeline sequences of the rocket engines. The first stage of the launch vehicle propulsion system includes four RD-870 rocket engines. A nonlinear mathematical model of low-frequency dynamic processes of the POGO-suppressor with bellows separation of liquid and gaseous media is presented. A significant effect of cavitation in the pumps of engines and the POGO-suppressor installation to the LOX feedline on the propulsion system dynamic gains is shown. Based on the developed mathematical model of the clustered rocket propulsion start-up, the studies of the Cyclone-4M main engines’ start-up transients were carried out. The asynchronous start-up timeline sequences of the rocket engine and the places of installation of the POGO-suppressors in the LOX feedline branches to the RD-870 rocket engine – near the general feedline collector as standard placement or directly at the entrance to the engines – were investigated. The analysis of start-up transients in the oxidizer feed system of the considered propulsion (the time dependences of the flowrate and pressure at the engine inlet) showed the following. Firstly, while the synchronous start-up of the engines, the installation of the POGO-suppressors near the feedline collector makes it possible to eliminate all engine inlet overpressures that exist in the rocket propulsion system in case of the absence of the POGO-suppressors. Secondly, the RD-870 engine asynchronous start-up operation affects negatively the time dependences of the propellant flowrate and pressure at the engine inlet if the POGO-suppressors are located near the feedline collector. So, in the propulsion system’s start-up timeline interval 0.95 s - 1.35 s, for some computational variants of the initial moments of the engine operation start, an abnormally large drop in the LOX flow rate and the overpressures at the engine inlet is observed. The asynchronous start-up of the RD-870 engines with the installation of the POGO-suppressors at the engine inlet does not significantly change the start-up transients compared to the synchronous starting of the engines. Thirdly, thus, it is shown that the installation of the POGO-suppressors both at the engine inlet and at the RD-870 branches near the collector has a significant positive effect on the quality of start-up transient processes for the main engines of the 1st stage of the Cyclone-4M launch vehicle. Placing the POGO-suppressors at the engine inlets is not standard and is considered without reference to the propulsion system layout. Nevertheless, the POGO-suppressors installed at the inlet to the engines are an effective means of preventing overshoots and dips in the parameters of the liquid-propellant rocket engine, including the conditions of asynchronous starting of the liquid rocket engines in the clustered propulsion system. The results obtained can be used in mathematical modeling of the start-up of the first stage propulsion system either for multistage sustainer rockets used in parallel with booster rockets or for the clustered multi-engine rocket propulsion system containing POGO-suppressors.
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Petukhov, S. A., L. S. Kurmanova, M. P. Erzamaev, D. S. Sazonov et D. S. Chinchenko. « Improving the Environmental Safety of Transport Engines Using Modified Engine Oil ». Ecology and Industry of Russia 24, no 1 (10 janvier 2020) : 9–13. http://dx.doi.org/10.18412/1816-0395-2020-1-9-13.
Texte intégralRésumé :
The problems of reducing emissions of harmful substances by transport engines are considered. It has been established that the use of modified engine oil is an effective way to increase the environmental safety of transport engines. The effectiveness of additives to improve the backsize of motor oil and reduce harmful emissions in the exhaust gas was evaluated. Methods for feeding additives are proposed. Technical solutions for the use of additives for transport engines have been developed. Experimental studies are presented to assess the effect of modified engine oil on the environmental safety of an engine.
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Sapate, Kumar D., et A. N. Tikekar. « Mechanical Modifications to Convert Small Two Strokes Carbureted Engine to Electronic Fuel Injection System Engine to Reduce Emission and Fuel Consumption ». Advanced Materials Research 768 (septembre 2013) : 213–17. http://dx.doi.org/10.4028/www.scientific.net/amr.768.213.
Texte intégralRésumé :
The evolution of four stroke engines and improved environmental pollution control norms has pushed the two-stroke engines towards obsolescence due to their inherent design problems. This has made the existing manufacturers & users of two-stroke engines a setback. In this paper attempt has been made to high light the performance parameters in respect of fuel efficiency and emission control. In this research work an effort is made to retrofit the commonly used two stroke engine for optimal performance by using EFI engine. It mainly includes injector locations with reference to spark plug which decides the combustion efficiency of engine. It also includes the location of different sensors and subsequent modification of silencer. As the automobile engine has to operate at higher speeds, proper and firm mounting of different electronic part is essential which affects the performance of engine. After mechanical modification of engine with EFI system it is tested by connecting it to dynamometer. The results are compared with that of carbureted engine.
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Langston, Lee S. « For Jet Engine Wing Mounting ». Mechanical Engineering 140, no 09 (1 septembre 2018) : S52—S53. http://dx.doi.org/10.1115/1.2018-sep4.
Texte intégralRésumé :
The mounting of a jet engine under the wing of an airliner can be a daunting task for turbofan engineers. Thrust forces generated by gas path momentum flow changes in a jet engine are transmitted by pressure (and friction) forces on stators and struts attached to the engine case. Case engine mounts then transmit the thrust forces (as high as 100,000 pounds thrust on the largest engines) to the wing pylons to pull the plane forward. The mounts must also support the engine weight (as high as 20,000 pounds) and carry nacelle flight loads. Engine bypass ratios are increasing (12:1 on the new geared fan engines), with fan sizes ever growing (178 inch diameter fan on the new GE9X). Mounting these new engines under a wing can present new challenges. During the early days of its introduction in the late 1960’s, Boeing’s iconic 747 jumbo jet had engine mount problems. These are examined, together with their solution.
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Xiang, La, Gerasimos Theotokatos, Haining Cui, Keda Xu, Hongkai Ben et Yu Ding. « Parametric Knocking Performance Investigation of Spark Ignition Natural Gas Engines and Dual Fuel Engines ». Journal of Marine Science and Engineering 8, no 6 (22 juin 2020) : 459. http://dx.doi.org/10.3390/jmse8060459.
Texte intégralRésumé :
Both spark ignition (SI) natural gas engines and compression ignition (CI) dual fuel (DF) engines suffer from knocking when the unburnt mixture ignites spontaneously prior to the flame front arrival. In this study, a parametric investigation is performed on the knocking performance of these two engine types by using the GT-Power software. An SI natural gas engine and a DF engine are modelled by employing a two-zone zero-dimensional combustion model, which uses Wiebe function to determine the combustion rate and provides adequate prediction of the unburnt zone temperature, which is crucial for the knocking prediction. The developed models are validated against experimentally measured parameters and are subsequently used for performing parametric investigations. The derived results are analysed to quantify the effect of the compression ratio, air-fuel equivalence ratio and ignition timing on both engines as well as the effect of pilot fuel energy proportion on the DF engine. The results demonstrate that the compression ratio of the investigated SI and DF engines must be limited to 11 and 16.5, respectively, for avoiding knocking occurrence. The ignition timing for the SI and the DF engines must be controlled after −38°CA and 3°CA, respectively. A higher pilot fuel energy proportion between 5% and 15% results in increasing the knocking tendency and intensity for the DF Engine at high loads. This study results in better insights on the impacts of the investigated engine design and operating settings for natural gas (NG)-fuelled engines, thus it can provide useful support for obtaining the optimal settings targeting a desired combustion behaviour and engine performance while attenuating the knocking tendency.
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Vincent, Wenny, Astuti Winda et Mahmud Iwan Solihin. « Intelligent Automatic V6 and V8 Engine Sound Detection Based on Artificial Neural Network ». E3S Web of Conferences 130 (2019) : 01035. http://dx.doi.org/10.1051/e3sconf/201913001035.
Texte intégralRésumé :
The sound of V6 or V8 engines has its own cultural appeal that cannot be replaced by the modern four-cylinder naturally aspirated or turbocharged engines. The identification of the type of engine by the sound is not an easy task, even for the professionals. An intelligent system that can identify V6 to V8 engines from various cars will give an insight of the features in the engine sounds that characterized the two different engines. In this work, an Artificial Neural Network (ANN) approach is applied for identifying cylinder of the engine based on the engine sound identification is proposed. The recorded sound of the engine is then processed in order to get some features which later be used in the proposed system. The Fast Fourir Transform (FFT) is adopted as a feature and later used as input to the Artificial Neural Network (ANN) based identifier. The Experimental results confirm the effectiveness of the proposed intelligent automatic six cylinder and eight cylinder engine based on Fast Fourier Transform (FFT) and Artificial Neural Network (ANN), since it resulting the training and testing accuracy of 100 % and 100 %, respectively.
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Li, Yufeng, Hua Zhao, Ben Leach et Tom Ma. « Charge Stratification in a Strong Tumble SI Engine(S.I. Engines, Stratified-Charge Combustion) ». Proceedings of the International symposium on diagnostics and modeling of combustion in internal combustion engines 2004.6 (2004) : 505–12. http://dx.doi.org/10.1299/jmsesdm.2004.6.505.
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Клушин, A. Klushin, Горчаков et Yuriy Gorchakov. « THE FORCING OF AUTOMOBILE ENGINES ». Alternative energy sources in the transport-technological complex : problems and prospects of rational use of 2, no 1 (27 avril 2015) : 33–36. http://dx.doi.org/10.12737/13835.
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One of ways of speeding up of engines is increasing of density of a fresh charge. Density of a charge can be increased by pressurization, by addition of an oxidizer in an engine power supply system - as such oxidizer N2О nitrous oxide - and by direct use of thermal energy of the fulfilled gases can serve in the engine. Three ways of speeding up of automobile engines are considered. Recommendations about use of ways of speeding up of engines are given in standard engines.
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Лазарева, Ю. И., С. В. Клименко, А. В. Кулик et И. В. Лазарев. « АНАЛИЗ СОВРЕМЕННОГО СОСТОЯНИЯ И ПЕРСПЕКТИВЫ РАЗВИТИЯ РАКЕТНЫХ ДВИГАТЕЛЕЙ ДЛЯ ИССЛЕДОВАНИЯ ДАЛЬНЕГО КОСМОСА ». System design and analysis of aerospace technique characteristics 27, no 2 (17 mai 2022) : 50–58. http://dx.doi.org/10.15421/471923.
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The article analyzes the current state and development prospects of rocket engines for space exploration. Currently, for flights to other planets, not to mention the stars, the use of liquid-propellant and solid-propellant rocket engines is becoming increasingly unprofitable, although many rocket engines have been developed. Thus, to reach manned planes even the nearest planets, it is necessary to develop rocket launchers on engines operating on principles different from chemical propulsion systems. The most promising in this regard are electric, laser and nuclear rocket engines, as well as hybrid rocket engines such as solid-state nuclear rocket engine (NRE) and electric jet engine (ERE) or gas-phase NRE and ERE.
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Sabaruddin, Ainul Aniyah, Surjatin Wiriadidjaja, Dayang Laila Abang Abdul Majid, Harijono Djojodihardjo et Mohamed Tarmizi Ahmad. « An Investigation on the Effect of Variable Valve Timing on Piston Engine for Lightweight Aircraft ». Applied Mechanics and Materials 225 (novembre 2012) : 245–49. http://dx.doi.org/10.4028/www.scientific.net/amm.225.245.
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As the Lycoming engine had failed its attempt on using variable valve timing for aircraft piston engine back in 1940s, the idea of the technology was abandoned as the turbines were then introduced in the aviation for better performance and greater power. Since piston engines produce smaller power efficiently in the low speed than turbine engines, they are presently still practically used in most of lightweight aircraft. With the use of a variable valve timing mechanism, it may help to increase the amount of air inlet and to provide more power output with lesser fuel consumption. With the use of this new valve system, improvements in the performance of automobile engines have been recorded. The indicated improvements, however, are limited to automobile engines running with high revolutions only. Engine simulation program was run in this investigation as an attempt to predict engine performances that are appropriate for lightweight aircraft.