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EN
This paper presents a method for the precise diagnosis of a diesel engine in an agricultural tractor based on the analysis of efficiency changes and parameters characterizing the process of fuel-air mixture preparation. We proposed that the technical condition be identified based on available data from the engine controller, as this enables the implementation of precise online diagnostics of an agricultural tractor. The method was verified using the original cycle, during which we simulated several engine defects leading to a change in conditions and quality of the processes of creating and burning the fuel/air/flue gas mixture. In the paper, we justified the selection of the points at which the engine parameters were measured, as they provide the most information and allow for efficient identification of damage. These results indicate the possibility of damage identification without the use of the diagnostic cycle in the operation of operator-driven vehicles and autonomous vehicles.
PL
W artykule przedstawiono rys historyczny odlewania tłoków silników spalinowych na przykładzie 50. lat doświadczenia Federal-Mogul (FM) Gorzyce sp. z o.o. Zwrócono szczególną uwagę na zmiany w konstrukcji układu chłodzenia kokilarek, które obecnie są sprzężone z robotami zalewającymi ciekły stop tłokowy Al-SiCu-Ni-Mg. To rozwiązanie zapewnia równomierną krystalizację tłoków i optymalną wydajność procesu ich odlewania. Na skutek konieczności poprawy sprawności silnika, a tym samym zmniejszenia zużycia paliwa i emisji substancji szkodliwych dla środowiska, zmianie uległa również budowa tłoków. W zależności od rodzaju silnika, obecne tłoki posiadają różny kształt denka, którego krawędzie są przetapiane laserowo, niższą tzw. „koronę” tłoka i odchudzone ścianki wewnętrzne. Dla zapewnienia mniejszych strat tarcia układu: tłok-pierścienie-cylinder i wzmożonego chłodzenia części pierścieniowej, nowoczesne tłoki są wyposażone w komponenty (kanały solne, alfinowane wkładki pierścieniowe), a płaszcz tłoka jest poddawany zabiegom obróbki powierzchniowej. Stosowanie innowacyjnych rozwiązań w Federal-Mogul Gorzyce Sp. z o.o. zapewnia uzyskanie kompromisu pomiędzy produkcją silników o zmniejszonej pojemności skokowej i dużej mocy, przy jednoczesnym zachowaniu trwałości i niezawodności odlewanych dziś tłoków ze stopów aluminium.
EN
The article presents a historical overview of the casting of combustion engine pistons on the example of 50 years of experience of Federal-Mogul (FM) Gorzyce Ltd. Particular attention was paid to the changes in the design of the cooling system of the mold making machines, which are currently coupled with robots pouring liquid Al-Si-Cu-Ni-Mg piston alloy. This solution ensures uniform crystallization of the pistons and optimal efficiency of the casting process. As a result of the need to improve engine efficiency, and thus reduce fuel consumption and emissions of substances harmful to the environment, the design of the pistons has also changed. Depending on the type of engine, the current pistons have a different shape of the bottom, the edges of which are melted by laser, the lower, so-called „crown” of the piston and slimmed down inner walls. To ensure lower friction losses of the piston-rings-cylinder system and increased cooling of the annular part, modern pistons are equipped with various components (salt channels, and alfinated ring inserts), and the piston skirt is subjected to surface treatment. The use of innovative solutions at Federal-Mogul Gorzyce Ltd provides a compromise between the production of engines with reduced displacement and high power, while maintaining the durability and reliability of today’s cast aluminum alloy pistons.
EN
The article presents the concept of a hybrid propulsion unit for ultralight aircraft. A combustion unit and an electric motor/generator were presented. As part of the research, a dedicated combustion engine controller and a two-way converter for energy conversion were built. The prototype drive unit was installed on a test stand and its initial characteristics were determined. The results of research and conclusions related to the construction of a hybrid drive unit are presented.
PL
W artukule przedstawiona została koncepcja hybrydowej jednostki napędowej dla ultralekkich statków powietrznych. Przedstawione zostały jednostka spalinowa a także silnik/generator elektryczny. W ramach badań zbudowany został dedykowany sterownik silnika spalinowego i dwukierunkowa przetwornica do konwersji energii. Prototypowy zespół napędowy zabudowano na stanowisku badawczym i wyznaczono jego wstępne charakterystyki. Przedstawiono wyniki badań i wnioski związane z budową hybrydowej jednostki napędowej.
EN
The present study was focused on the combustion engine with a variable compression ratio (VCR), namely the four-stroke air-cooled engine with the active combustion chamber (ACC). An indicated pressure, torque, power, and specific fuel consumption of that engine were investigated experimentally as a goal of the present study. Experiments were conducted using two versions of an engine. Two parameters particularly influencing the ACC engine performance including the maximum compression ratio CRmax and the indicator γfm determining the correct operation of the ACC system, were described. It was found that the ACC engine allowed avoiding detonation combustion without changing the amount and composition of the combustible mixture, and even without delaying the ignition advance angle. In addition, the possible range of control of the combustion process allowed the ACC engine to operate with different types of hydrocarbon fuels, for example, in the form of petrol with various alcohol admixtures. The very intense flow of the combustible mixture inside the cylinder of the ACC engine allowed describing the combustion in the ACC engine with zero-dimensional mathematical models with the dual Vibe function providing the proper characterization of the heat release process. The use of very high maximum compression ratios allows the ACC engine to operate to a certain extent as a Homogeneous Charge Compression Ignition (HCCI) engine with high lambda coefficients.
EN
The article analyzes and evaluates costs, transport time and CO2 emissions by selected vans. The research was carried out on the example of three models of Iveco Daily vehicles powered by: diesel oil, electricity and compressed natural gas (CNG). The result of the research presented in the article is the determination of the operating costs of vehicles powered by various energy sources and the level of CO2 emissions. The comparative analysis was carried out on real data for the established transport task. Vehicles with engines powered by compressed natural gas are characterized by the highest savings in terms of transport costs. As the authors pointed out, this may be due to the fact that this type of engines, despite the low interest of buyers at the moment, may gain much more popularity in the future. On the other hand, in relation to vehicles with electric motors, the cost of transport is the highest, which means that this type of technology is ineffective in relation to long-distance transport.
EN
The flow of exhaust gases is the source of many physical processes, including thermal, acoustic, mechanical and chemical phenomena with high dynamics of changes. The study analyzes the impact of the entire structure of the exhaust system on the formation of acoustic energy, determining the transmission loss characteristics of its individual components and the entire system. On the example of a structure based on a proprietary solution of an adjustable reactive muffler, the possibilities of shaping the flow of acoustic waves in the process of designing and selecting exhaust systems for internal combustion engines were determined. The study was carried out with the use of the CFD method and a specialized package for advanced simulations AVL AST.
EN
The article presents a method of determining the characteristics of exhaust emissions and fuel mass consumption in real driving conditions based on a single test using the Monte Carlo method. The exhaust emission characteristics used are the relations between the emissions and the average vehicle speed, and the characteristic of the fuel mass consumption is the dependence of the fuel mass consumption at the average vehicle speed. The results of empirical research of a passenger car with a spark-ignition engine in the RDE test were used. The use of the Monte Carlo method made it possible to select the initial and final moments of averaging the process values, thanks to which it was possible to determine the discrete values of the characteristics for various values of average vehicle speeds. The determined discrete characteristics of the particulate mass and number emissions and fuel mass consumption relative to the average vehicle speed were approximated by polynomial functions of the second and third degree. The determined discrete characteristics, presented as sets of points, were characterized by a relatively small dispersion in relation to their polynomial approximations. The average relative deviation of the points of discrete characteristics from the value of the polynomial was in most cases small – less than 4%, only in the case of the number of particles emitted deviated from this, as the average relative deviation of the measured points from the determined polynomial was nearly 14%. Combined with the results of RDE empirical studies, the Monte Carlo method proved to be an effective method for determining the characteristics of exhaust emissions, measured in real vehicle operating conditions. The main advantage of the proposed method was a significant reduction in the actual workload necessary to carry out the empirical research – where it became possible to determine the characteristics in a large range of vehicle average speed values with just one drive test. Using standard methods of measuring this type of data, it would be necessary to conduct multiple tests, driving at different average vehicle speeds.
EN
The article deals with the study of exhaust emissions from a combustion engine in the Real Driving Emission (RDE) test. These tests are a simulation of real conditions of use of motor vehicles. Nowadays, RDE tests are mandatory for Light Duty Vehicle (LDV) and Heavy Duty Vehicle (HDV) vehicles and in the future, restrictive standard. Euro 7, which combines stricter limits with a comprehensive RDE test cycle, is becoming a challenge for current vehicle engineering. The paper presents the results of pollutant emission tests from a passenger car (PC). In the tests of LDV in the RDE test, the results of which are analyzed in the article, the Portable Emissions Measurement System (PEMS) mobile exhaust emission testing system was used. The processes describing the operating states of the vehicle and the combustion engine, as well as the processes of exhaust emission intensity and the intensity of the number of particulate (PN), were examined. The correlation between the considered processes was investigated. The emission of carbon monoxide, hydrocarbons, nitrogen oxides, particulate and carbon dioxide as well as the road PN were examined. The zero-dimensional statistical characteristics of the examined processes were also determined. The probability density and power spectral density of the processes were established. A great diversity was found in the properties of the process distributions, as well as in the dynamic properties of the processes. In the summary of the analysis of the results of the car speed process, the operating states of the combustion engine and the processes of exhaust emission intensity and the process of the intensity of PN in the RDE test, conclusions were formulated regarding, among others, course of the intensity of these compounds, correlation of the processes of pollution emission intensity and the intensity of the PN with the process of car speed, distribution of processes.
EN
The process of cylinder charge - air sucked into the cylinder - transformation during engine start-up phase is characterized. Heat exchange and air flow through piston-cylinder group leakage processes are described as factors influencing the gas thermodynamic parameters. The Woschni formula based on similarity theory was finally used as equation describing heat transfer in combustion engines cylinder. The computational model for cylinder charge parameters in the whole engine cycle during its starting at low temperature is presented. Some taken assumptions and characteristics of partial processes resulting from the computations are shown. There are indicated the possibilities of using the model at internal combustion engine diagnostic process.
EN
In order to ensure better control of the combustion process in a internal combustion engine powered by hydrogen, it has been proposed to use a split combustion chamber solution. Following paper contains a description of a hydrogen combustion system that includes an analysis of possible technical solutions. The considerations take into account the issues of the dual nature of hydrogen knocking and the problem of burning a stratified charge of a hydrogen-air mixture in a cylinder.
EN
The use of comfort systems, the number of which in vehicles is constantly increasing, has a direct impact on fuel consumption and engine load. As part of the article, the vehicle's drive in real operating conditions was analyzed in terms of the emission of toxic compounds. The tests were carried out without and with the systems turned on, using the PEMS apparatus, where road emissions of carbon dioxide, carbon monoxide, hydrocarbons, nitrogen oxides and solid particles were measured in terms of mass, number and size distribution of diameters. The track was driven four times with different setting of the powertrain of examined car. The differences concerned the number of comfort systems in the vehicle and the mode of operation of the combustion engine.
EN
The paper describes the method of determination of exhaust emission characteristics from a vehicle engine based on the results obtained in a driving test simulated on an engine dynamometer. These characteristics are the relations between the specific distance emissions and the zero-dimensional characteristics of the process of vehicle velocity: the average velocity value and the average value of the absolute value of the product of vehicle velocity and acceleration. The exhaust emission characteristics are used to simulate the emissions from vehicles operating in different types of traffic conditions. The engine operating states in the engine dynamometer tests were determined by the operating conditions of the vehicle during the test. The authors applied the Monte Carlo method in order to determine the characteristics of different values of the zero-dimensional characteristics of the vehicle velocity process. This enabled the determination of the characteristics based on the test results from a single realization of the process of vehicle velocity. Additionally, the developed method allowed a replacement of the empirical research on the chassis dynamometer with the one performed on the engine dynamometer. The obtained exhaust emission characteristics are in line with the characteristics obtained on the chassis dynamometer in multiple tests.
EN
Contemporary operation-related requirements for combustion engines force the necessity of ongoing assessment of their in operation technical condition (e.g. marine engines). The engine efficiency and durability depend on a variety of parameters. One of them is valve clearance. As has been proven in the paper, the assessment of the valve clearance can be based on vibration signals, which is not a problem in terms of signal measurement and processing and is not invasive into the engine structure. The authors described the experimental research aiming at providing information necessary to develop and validate the proposed method. Active experiments were used with the task of valve clearance and registration of vibrations using a three-axis transducer placed on the engine cylinder head. The tests were carried out during various operating conditions of the engine set by 5 rotational speeds and 5 load conditions. In order to extract the training examples, fragments of the signal related to the closing of individual valves were divided into 11 shorter portions. From each of them, an effective value of the signal was determined. Obtained total 32054 training vectors for each valve related to 4 classes of valve clearance including very sensitive clearance above 0.8 mm associated with high dynamic interactions in cylinder head. In the paper, the authors propose to use a convolutional network CNN to assess the correct engine valve clearance. The obtained results were compared with other methods of machine learning (pattern recognition network, random forest). Finally, using CNN the valve clearance class identification error was less than 1% for the intake valve and less than 3.5% for the exhaust valve. Developed method replaces the existing standard methods based on FFT and STFT combined with regression calculation where approximation error is up to 10%. Such results are more useful for further studies related not only to classification, but also to the prediction of the valve clearance condition in real engine operations.
EN
Internal combustion engines represent the largest share of motor vehicle propulsion types. Despite the introduction of alternative drives (hybrid and electric), combustion engines will continue to be the main factor in the development of transport. Therefore, work related to their technological development and reduction of their harmful effects on human health and the environment is required. The development of internal combustion engines can be seen in two directions: technological changes resulting in increased efficiency of such engines and the second direction connected with limitation of exhaust gas emission. The present work is included in the second direction of research interests and concerns the analysis of various operating conditions of internal combustion engines. The operating states, both static and dynamic, determine the operational properties of internal combustion engines, such as fuel and energy consumption as well as pollutant emissions. Sofar, such operating conditions have only been mapped on a chassis dynamometer in various homologation tests. The course of the type approval test was known and the conditions of measurement were also known, which made it impossible to introduce a random factor into such tests. Currently, these properties are determined in tests performed in real vehicle operating conditions – RDE (Real Driving Emissions). Such tests are representing real operating conditions of motor vehicles. Limitations for performing tests in real traffic conditions are, apart from formal requirements concerning the duration and distance of individual parts, the dynamic conditions of vehicles determined by the speed and acceleration of the vehicle. The study analyzed the properties of vehicle speed processes and engine operating states in the RDE test, taking into account its individual phases – driving in urban, rural and motorway conditions. Engine operation states are the processes of the engine rotational speed and its relative torque. It was found that the dynamic properties of the vehicle speed process are much more significant than the engine operating states. It was also found that the road emission of pollutants in the RDE test, which is the property of vehicles measured in the test, the motorway phase properties have greatest impact.
EN
This paper presents the research results for a diesel and hydrogen fueled engine. The research object is a four-cylinder, four-stroke ADCR engine with a displacement of 2,636 cm3. In the experiments, glow plugs were replaced with compressed hydrogen injectors and a special adapter. Hydrogen was supplied directly into a combustion chamber using a test injector. A hydrogen dose in the tests was changed at selected test points and ranged from 0 to 160 dm3/min. The research were conducted at 1,500 rpm. A hydrogen injection start angle and maximum hydrogen dose were specified from the preliminary experiments. The following parameters were analyzed: indicated mean effective pressure, maximum pressure, crank angle of maximum cylinder pressure occurrence and heat release. The obtained results were statistically analyzed. The conducted analysis focused on determining whether there are significant differences between early and late injection and how these changes affect the measured parameters.
PL
W artykule przedstawiono podstawowe typy przepływomierzy powietrza, stosowane w silnikach spalinowych samochodów: z klapą spiętrzającą, HLM, HFM, Vortex i MAP. Przedstawiono wyniki badania tych przepływomierzy na specjalnie przygotowanym stanowisku pomiarowym. Przeanalizowano możliwość ich zamiany i zweryfikowano taką możliwość w praktyce.
EN
The article presents the basic types of air flow meters used in internal combustion engines of cars: with a damming flap, HLM, HFM, Vortex and MAP. The results of testing these flow meters on a specially prepared measuring stand are presented. The possibility of replacing them has been analyzed and this possibility has been verified in practice.
EN
The paper discusses the application of an in-cylinder catalyst allowing a reduction of the exhaust emissions from a diesel engine. Its placement in the combustion chamber, the area where the process of combustion takes place, allows reducing the emissions (carbon monoxide, hydrocarbons, particulate matter) ‘at source’. The paper presents the possibilities of boosting the efficiency of catalysts in diesel engines by extending the time of heating of a glow plug (the catalyst applied on the glow plug). The tests were performed for the following conditions: no heating (marked 0+0), glow plug heating for 60 s after engine start (marked 0+60), glow plug heating prior to engine start for 60 s and glow plug heating for 60 s after engine cold start (marked 60+60). An improvement in the efficiency of oxidation of the exhaust components was observed as the glow plug heating time increased.
EN
Objective of this work was to realize a test of durability of railway engine EMD645 with power about 1300 kW. Within the framework of this test were investigated a prototyped piston’s rings with diamond embankment. Piston rings are made of chromium layer with including of diamond powders technology with a porous chromium coating, where in pores is deposited on said diamond powder with a grain size about 1 micron. The work will be carried out of an analysis of collaboration piston-piston rings-cylinder unit in internal combustion engine and an analysis of the use of hard materials (diamond powder) in friction pairs. During work of this unit we can observe wear of piston rings, precisely - of coating which is deposited on ring to prolong service life. After testing of the locomotive engine EMD645 on the basis of the collected results are developed conclusions of the wearing intensity on piston ring and relating them to the requirements for coatings. The work aims to show the possibilities and benefits of the application of new protective coatings on structural elements of the internal combustion engine in order to reduce their wearing, which is consistent with the observed trend of technology development.
19
Content available Methodological basis of road acoustic researches
EN
Transport is one of the most burdensome negative sources affecting the natural environment. Long-term exposure of the body to exhaust pollution can cause health problems and, in the worst case, even lead to death. In addition to exhaust emissions, traffic noise is another equally important issue. Due to its nature, variability over time or the design diversity of vehicles in the traffic flow, it is a phenomenon difficult to define. Like exhaust pollution, it affects people's health and quality of life. In addition to its direct impact on the human physical system, it can also cause psychosomatic disorders, which is why a detailed analysis of road noise taking into account the real operation of the vehicle is so important. The paper presents the basic concepts related to the problem of traffic noise in the world, determines the sources of noise in vehicles and the methodology of conducting acoustic road tests. At the final stage of the scientific paper, methods of reducing excessive noise levels in large urban agglomerations were also presented, and the effectiveness of using noise barriers on selected parts of the city road network using proprietary acoustic tests was assessed.
EN
This paper presents an analysis of selected propulsion units dedicated to test stands for unmanned aircraft systems. It focuses on engines suitable for aircraft with a maximum take-off mass up to 150 kg. The study includes an analysis of propulsion units that can be used to power systems on stationary test stands dedicated to advanced research and measurement of prototype aerospace technologies intended for use in rotorcraft. The analysis of propulsion units shows that electric units are a better choice for powering UAV rotorcraft test stands. Their main advantages include the possibility to simplify the construction of the device by eliminating gears and to mount the motor in a vertical position, simpler power supply, cooling and control systems and the lack of an exhaust system. Additional advantages are undoubtedly lower vibration generation, cheaper and easier operation as well as better comfort.
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