The calculation of the four-stroke cycle of a diesel engine supercharged with uneven alternation of inlets

Based on the analysis of the structure of a quasi-stationary mathematical model of the working cycle of a piston engine cycle, the algorithm and method of calculation of working processes in diesel engines with gas turbine charging at nonuniform alternating inlets to the cylinders with fresh charge are presented. It is shown that the efficiency of joint operation of the engine and turbocharger is greatly influenced by the nature of fluctuations during the working cycle of air flow and boost pressure which determine the efficiency of the compressor and the entire power plant. For the coordination of their operation, an approximate calculation using a certain algorithm is proposed. After selecting the turbocharger and charge air cooler, the boost parameters are adjusted to the technical data of the selected turbochargers and the final initial data for the calculation of the engine boost system are drawn up. At further calculation, the flow coefficients in the inlet and exhaust pipelines are corrected which ensures with the accepted relative error coincidence of the specified and calculated average values of pressures and weight of the working body leaving and entering the cylinder. In this case, the fuel injection advance angle, the duration of the ignition delay of the fuel–air mixture, and other parameters are adjusted. The proposed dependence is used to calculate the characteristics of heat release and the rate of heat release in the engine with compression ignition. The latter is not monotonous, since it causes the presence of two maxima of speed: at explosive and diffusion combustion of fuel.