CFD simulation to investigate hydrodynamics of oscillating flow in a beta-type Stirling engine

Stirling engines have recently been studied theoretically via two different methods, thermodynamic analysis and CFD simulation. Evidently, second order thermodynamic analysis is simpler and less time consuming than CFD. However CFD considers more details as well as the engine geometry and consequently reflects more details about the flow field and losses phenomena. In this paper, numerical simulation of a typical Stirling engine was conducted by OpenFoam open source software. Dynamic mesh was used to simulate moving pistons and the working fluid was considered compressible. Volume averaging technique was applied to simulate flow in the regenerator as a porous media. The well-established PIMPLE algorithm was used to handle pressure coupling in momentum equation. To investigate the effect of turbulence, a simulation was conducted employing k-ω SST turbulence model and no significant change in the results was observed.