Optimization on the Performance of an Irreversible Harmonic Brayton Heat Engine

A cycle model of an irreversible Brayton heat engine working with harmonic systems is established in this paper.Based on quantum master question and semi-group approach,the time evolution of the cycle is analyzed.General expressions of the times spent on two constant-frequency processes,work,thermal efficiency and power output are derived.Moreover,explicit curves between thermal efficiency and power output with the time of low constant-frequency processes are generated.By means of numerical analysis,the parameters of the performance of the heat engine cycle are optimized.