ABSTRACT

Heat losses to the environment may significantly affect engine performance. To accurately account for the heat-loss effect, engine performance simulation should be carried out based on a complete model which includes all four strokes of an engine cycle. In this paper, a mathematical model that includes the intake stroke, compression stroke, combustion and expansion stroke, and exhaust stroke is presented, which incorporates heat losses to the environment during the four-stroke diesel engine cycle. Through the simulation, the temperature and pressure profiles in the cylinder as well as the engine thermal efficiency are obtained. The profile of heat transfer coefficient is generated, and the effect of heat transfer to the environment on the engine performance is discussed in conjunction with the optimization of the engine performance. As a comprehensive mathematical model for engine simulation, this model is proven to be accurate, convenient, and fast, based on comparisons with available experimental data.