Influence of Compression Ratio on Pressure in the Cylinder of Internal Combustion Engine

Abstract Currently, engines with variable compression ratios are not used, presumably due to the complexity of the design. Regulating the compression ratio is a complex problem, for which various engines are being developed that differ in design, kinematics, method of regulating the load and changing the compression ratio. This paper presents the results of calculating efficiency and fuel consumption for crankshaft speeds of 2000 rpm and 4000 rpm with a compression ratio of 8.6 and a rotation speed of 4000 rpm with a compression ratio of 13 and combustion characteristics m = 3 and m = 1 are presented. It is shown that these characteristics at higher speeds approach those at lower speeds with increasing compression ratio. The engine parameters were calculated for various modes based on Wiebe theory. Based on the above calculations, efficiency and fuel consumption are determined for the corresponding modes and nature of engine operation. As a result of the calculations, it was obtained: with an increase in the crankshaft rotation speed, the Cycle Efficiency Coefficient will decrease by almost half and fuel consumption will accordingly increase; with an increase in the compression ratio, the Efficiency Coefficient is restored and fuel consumption is accordingly reduced.