Influence of Multi-irreversibilities on the Performance of a Otto Heat Engine

An irreversible cycle model of the Otto heat engine is established, in which the variable heat capacities of the working fluid, the heat leak losses, the irreversibility of working fluid resulting from the adiabatic processes and the internal friction loss are taken into account. Based on the cycle model, mathematical expressions for the efficiency and power output of the cycle are derived. By using numerical solution method, the cyclic performance characteristic curves and the optimal operating regions of main parameters are evaluated. Moreover, the varieties of irreversible effects on the cycle performance are discussed.