Numerical analysis of heat transfer area effect on cooling performance in regenerator of free-piston Stirling cooler

This study numerically investigated the cooling characteristics of a free-piston Stirling cooler (FPSC), which is considered as an alternative cooling system. In particular, the effect of the heat transfer area of the regenerator on the cooling performance and pressure loss of the FPSC was estimated. Commercial code ANSYS Fluent (v.17.2) was used for numerical analysis. A thermal non-equilibrium model was adopted to consider the effect of the heat transfer area of the wire mesh type regenerator. Furthermore, the dynamic mesh method was used to simulate the behavior of the dynamic components. As the heat transfer area of the regenerator increased, the cold end temperature that reached the quasi-steady state decreased. However, simultaneously, the pressure drop of the regenerator increased, which increased the input PV power required to drive the FPSC and decreased efficiency.