MATHEMATICAL MODEL OF PETROL ENGINE WORKING ON ATKINSON CYCLE

Abstract

The article discusses ways to improve the fuel efficiency of internal combustion engines. The main approaches to improving the fuel efficiency of automotive engines are considered. Improving the fuel economy of cars by regulating the degree of compression on the partial modes of the engine and controlling the load by changing the valve timing. Gasoline internal combustion engines operate in a narrow range of changes in the composition of the working mixture, therefore at partial loads it is necessary to reduce the mass of the working body to maintain the required composition of the mixture. This is ensured by throttling the air entering the cylinders, which leads to a significant deterioration in the indicator indicators of the internal combustion engine due to an increase in pumping losses. The solution to the problem is a transition from throttling the air to mass regulation of the charge by delaying the moment of closing the intake valve, that is, adjusting the engine load according to Atkinson's method. For the internal combustion engine with load control according to the Atkinson method, the task is to select a design scheme for the gas distribution mechanism and parameters of the working process. This is possible by developing certain calculation methods. The article proposes a general methodology and mathematical models of the elements and subsystems of the workflow of the internal combustion engine with Atkinson method load control, which allow making the choice of rational parameters of the engine design and workflow at the stages of its development, development and research. Empirical dependencies of engine operation parameters are obtained. The obtained empirical dependencies allow you to track the changes in the main parameters of the engine operating cycle. The mathematical model takes into account the kinematics of the engine, as well as options for controlling the load of the engine and the degree of compression according to the Atkinson method. According to the results of theoretical studies using the mathematical model of the engine workflow, the load characteristics of the engine with load regulation according to the Atkinson method and the engine operating in the Otto cycle are constructed. It is noted that the regulation of the load by the Atkinson method is advisable to use at low speed, and with increasing speed go to the use of other auxiliary elements of the engine design. For example, a mechanical supercharger.