Effects of residual gas fraction and stroke ratio on the performance and entropy generation of an irreversible Otto cycle

Finite-time thermodynamics is often used in realistic analysis of the performance of heat engines. In this study, the effects of residual gas fraction and stroke ratio on engine performance and entropy generation were investigated by taking into consideration the losses such as heat transfer and friction for irreversible Otto cycle. As a result, with the increase of the residual gas fraction, the initial cycle temperature and brake specific fuel consumption increase while the maximum cycle temperature, effective power, thermal efficiency and entropy generation decrease, with the increase of the stroke ratio, the brake specific fuel consumption and entropy generatin increases