| Abstract: | A cyclic model of an irreversible Diesel heat engine is presented, in which the heat loss between the working fluid and the
ambient during combustion, the irreversibility inside the cyclic working fluid resulting from friction, eddies flow, and other
irreversible effects are taken into account. By using the thermodynamic analysis and optimal control theory methods, the analytical
expressions of power output and efficiency of the Diesel heat engine are derived. Variations of the main performance parameters
with the pressure ratio of the cycle are analyzed and calculated. The optimum operating region of the heat engine is determined.
Moreover, the optimum criterion of some important parameters, such as the power output, efficiency, pressure ratio, and temperatures
of the working fluid at the related state points are illustrated and discussed. The conclusions obtained in the present paper
may provide some theoretical guidance for the optimal parameter design of a class of internal-combustion engines. |
