The influence of cylinder wall temperature profile on the second-law diesel engine transient response

A developed software is used to study the effect of the cylinder wall temperature profile on the second-law transient performance of a turbocharged diesel engine. The simulation, based on the filling and emptying approach, includes analysis of mechanical friction per degree crank angle, mathematical simulation of the fuel pump, while each equation in the model is solved separately for every cylinder of the six-cylinder diesel engine under study. The model is validated against experimental data for various load changes. A second-law analysis is performed for every process of the diesel engine covering its transient operation. The effect of the cylinder wall temperature profile on the second-law transient response of the engine is depicted in detailed, multiple diagrams. Special reference is made to the interesting low heat rejection (“adiabatic”) case. It is shown from the analysis that after a ramp increase in load the second-law terms including the various irreversibilities ones, unlike their first law counterparts, are heavily impacted by the cylinder wall temperature variation, thus providing an increased potential for extra work recovery. This fact best highlights the results of the second-law analysis and its diversification as compared to the first-law theory.