scholarly journals Thermodynamic modeling of combustion process of the internal combustion engines – an overview

2019 ◽  
Vol 178 (3) ◽  
pp. 27-37 ◽  
Author(s):  
Denys STEPANENKO ◽  
Zbigniew KNEBA

The mathematical description of combustion process in the internal combustion engines is a very difficult task, due to the variety of phenomena that occurring in the engine from the moment when the fuel-air mixture ignites up to the moment when intake and exhaust valves beginning open. Modeling of the combustion process plays an important role in the engine simulation, which allows to predict in-cylinder pressure during the combustion, engine performance and environmental impact with high accuracy. The toxic emissions, which appears as a result of fuels combustion, are one of the main environmental problem and as a result the air pollutant regulations are increasingly stringent, what makes the investigation of the combustion process to be a relevant task.

2019 ◽  
Vol 178 (3) ◽  
pp. 182-186
Author(s):  
Zbigniew SROKA ◽  
Maciej DWORACZYŃSKI

The modification of the downsizing trend of internal combustion engines towards rightsizing is a new challenge for constructors. The change in the displacement volume of internal combustion engines accompanying the rightsizing idea may in fact mean a reduction or increase of the defining swept volume change factors and thus may affect the change in the operating characteristics as a result of changes in combustion process parameters - a research problem described in this publication. Incidents of changes in the displacement volume were considered along with the change of the compression space and at the change of the geometric degree of compression. The new form of the mathematical dependence describing the efficiency of the thermodynamic cycle makes it possible to evaluate the opera-tion indicators of the internal combustion engine along with the implementation of the rightsizing idea. The work demonstrated the in-variance of cycle efficiency with different forms of rightsizing.


2016 ◽  
Vol 822 ◽  
pp. 169-174
Author(s):  
Alexandru Mihai Dima ◽  
Dragos Tutunea ◽  
Marin Bica

The automotive industry represents one of the most important segments of the world economy that has to be in a continue development. The latest procedures for determination of an internal combustion engine performance have a big acquisition cost and demand special conditions even if the tested engine has smaller dimensions. The present paper presents other accessible solutions for this matter.


Author(s):  
Stephen A. Ciatti ◽  
Thomas Wallner ◽  
Henry Ng ◽  
William F. Stockhausen ◽  
Brad Boyer

Although hydrogen is considered one of the most promising future energy carriers, there are several challenges to achieving a “hydrogen economy,” including finding a practical, efficient, cost-effective end-use device. Using hydrogen as a fuel for internal combustion engines is seen as a bridging technology toward a large-scale hydrogen infrastructure. To facilitate high-efficiency, high-power-density use of hydrogen with near-zero emissions in an internal combustion engine, detailed analysis of the hydrogen combustion process is necessary. This paper presents thermodynamic results regarding engine performance and emissions behavior during investigations performed on a single-cylinder research engine fueled by pressurized gaseous hydrogen. Avoiding combustion anomalies is one of the necessary steps to further improve the hydrogen engine power output at high-load operation while, at the same time, reducing fuel consumption and emissions during part-load operation. The overall target of the investigations is an improved combustion concept especially designed for hydrogen-engine-powered vehicles. Future activities include performing optical imaging of hydrogen combustion by using an endoscope. We will also investigate supercharged external mixture formation, as well as hydrogen direct-injection operation.


1947 ◽  
Vol 157 (1) ◽  
pp. 387-404 ◽  
Author(s):  
L. J. Kastner

The mass of air taken in per unit time by an internal combustion engine is a quantity of considerable importance in any analysis of engine performance, and a convenient means of measuring this quantity will often be required by the research worker or development engineer. Where reciprocating engines are concerned, the problem of measurement is not easy, since the flow is of a pulsating nature, for which “constant flow” types of measuring apparatus will, in general, be unreliable. A few suitable methods for measuring pulsating flows have, however, been devised, and what is generally known as the “airbox method”—consisting of the use of a measuring orifice in conjunction with a smoothing capacity—has often been employed, mainly because of its simplicity and the ease with which the necessary apparatus can be constructed. The work of Watson and Schofield (Proc. I.Mech.E., 1912, p. 517) has been of great value to users of the airbox method, but, though it has to some extent been supplemented by later investigations, several important questions still remain unanswered. The experiments described in the present paper represent an attempt to furnish additional information, in particular as regards the amplitude of the pressure fluctuations occurring in boxes of inadequate size and the errors in measurement produced thereby, a simple theory being given to account for these latter. The various factors governing the design of a reliable airbox meter are discussed, and it is shown that they can be related to the value of a dimensionless criterion which may be determined for any given engine.


2015 ◽  
Vol 160 (1) ◽  
pp. 56-61
Author(s):  
Kazimierz ROMANISZYN

Modern vehicles with hybrid combustion-electric drive systems are an important element in the strategy for reducing fuel consumption and emissions of exhaust gas components. Determinant of the use and development is to achieve substantial benefits in terms of classical powertrain vehicles equipped with internal combustion engines. This paper presents the concept of kinematic ratio selection between the engine and the electric machine. This concept is based on the analysis of the internal combustion engine load caused by the resistances of motion and the best possible assessment of the additional load caused by the operation of the generator. It is proposed that the energy transferred to the generator was taken in a most preferred area of the engine performance characteristics and generator by changing kinematic ratio between the engine and the generator. The described concept can also be used for the recovery of vehicles braking energy.


2015 ◽  
Vol 75 (8) ◽  
Author(s):  
M. Hanif Mat Muhammad ◽  
A. Qaiyum Hanafiah ◽  
Aman Mohd Ihsan Mamat

Internal combustion engines are the main power source for  automobile vehicles.  As current  emission regulations becomes more stringent, more fuel efficient and less polluting engines are becoming the focus of car manufacturers. This paper presents the study of improving the performance of K3-VE I4 internal combustion engine that is used in the Perodua Myvi for the Perodua Eco-Challenge 2013. The strategy was  to use an EGR system to reduce Brake Specific Fuel Consumption (BSFC) while maintaining or increasing the engine power. The effects of different location of EGR on the engine performance were tested on a chassis dynamometer. The sensitivity of the engine performance and gas emission were studied since EGR implementation plays a  major role in influencing NOx emission. The performance parameter such as engine power and BSFC were then analysed. The result shows that a significant increase of power can be achieved and a reduction of around 56% was obtained on the BSFC. While the best NOx reduction was around 93%. These improvements are obtained at low RPM that corresponds to Perodua Eco-Challenge’s objective.  


To a large extent, road transport is responsible for air pollution. Emissions of exhaust gases from internal combustion engines are not only toxic, poisoning all biological organisms, but also create a greenhouse effect, contributing to the process of global warming. The elimination of these extremely undesirable phenomena is ensured by improving the environmental safety of road transport, which is implemented in various ways, including improving the combustion process of the fuel-air mixture in the cylinders of an internal combustion engine. Keywords automotive wheeled vehicles, fuel energy, internal combustion engines, environmental safety


Author(s):  
A. Katijan ◽  
A. H. Kamardin

The compression ratio has a significant impact on engine power, fuel economy, emission, and other performances of internal combustion engines. Basic engine theory states that a higher compression ratio produces higher torque and horsepower. One way of having different compression ratio is by changing piston head shape. A piston is a cylindrical engine component that slides back and forth in the cylinder bore via forces produced during the combustion process. The piston acts as a movable end of the combustion chamber transmitting power generated from the burning of fuel and air mixture in the combustion chamber. The objective of this study is to compare the engine performance in horsepower and torque produced by the different shapes of the piston head in an internal combustion engine. Three pistons with different head shapes -  standard, mug (low compression) and dome (high compression) with a compression ratio of 8.8:1, 7.61:1 and 10.06:1 were selected for the study. An experiment was also performed to a standard piston installed with 1.5 mm gasket, which has a compression ratio of 7.31. The experiments were carried out using a standard internal combustion engine of a Honda EX5 motorcycle. The engine runs on a chassis dynamometer to measure its torque and horsepower. Piston performance was evaluated based on the maximum available torque and horsepower. The result shows that all three pistons produce different torque and horsepower. The domed piston head produces higher torque and horsepower followed by the standard and mug. By just changing the piston head shape, torque and horsepower increased up to 7.14% and 20.05%  respectively.


2020 ◽  
pp. 40-43
Author(s):  
A. E. Korneev ◽  

The main topic of the article is the choice of the direction and implementation of the use of electronic measuring instruments and monitoring of the working process occurring in the diesel internal combustion engine. For this purpose, an analysis is performed and a device is created that allows controlling the uneven rotation of the engine crankshaft containing photoelectron sensors, one of which allows reading the moment of passing the upper dead point, the other is designed to control the angular speed of the flywheel. The device converts the signals of these sensors into the form necessary for visualization of the working periodic process on the oscilloscope screen. The article presents a block diagram of the device and its amplitude-frequency characteristic. This device can be used for research and development work to improve fuel supply systems in internal combustion engines


2019 ◽  
Vol 179 (4) ◽  
pp. 21-26
Author(s):  
Kazimierz LEJDA ◽  
Michał WARIANEK

The article presents selected methods of assessing the basic parameters of the combustion process, as well as assessing the usability and limitations of the methods used to determine the initiation and the end of the combustion process in reciprocating internal combustion engines. The methods considered are based on data contained in real, developed indicator diagrams. Basic thermodynamic assumptions and the scope of application of the combustion process evaluation method based on the actual work cycle of a combustion engine prepared in a double logarithmic scale were discussed. The article also mentions the application of the following methods: a direct pressure comparison method in the cylinder, the comparison of the first pressure derivative in the cylinder, logarithmic derivative method of pressure change in the cylinder, the method of the polytropic index, method of the first derivative of the polytropic index and the method of constant values of the polytropic index. The article presents the advantages and disadvantages of the research of our methods.


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