In this study, thermodynamic performance of a γ-type Stirling engine was studied by adjusting values of some parameters around a designated baseline case such as the effects of charged pressure, heating temperature, stroke, rotation speed, the equilibrium position of the piston, the phase angle difference between the piston and the displacer, and the porosity of regenerator on indicated power and thermal efficiency of the engine. The numerical simulation model is established based on turbulent flow assumption and the realizable k-ε model is employed to solve the flow and thermal fields in the engine. In regard to the flow in the regenerator, the Darcy-Forchheimer model was used to depict the dynamic behavior of the working fluid. Besides, the thermal equilibrium model was used for solving the energy equation. Finally, the working fluid in the engine undergoes a wide range of pressure and temperature so the effects of temperature and pressure on the viscosity and thermal conductivity of the working fluid are required to include. The thermal conductivity of the porous medium matrix is affected by the wide range of temperature as well.

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