External heat transfer enhancement of a beta-type Stirling engine with fins as regenerator

Abstract

The Stirling engine is an externally heat engine closed loop with a high theoretical performance and low emissions compared to other conventional engines. This property nowadays becomes very advantageous due to its multi-fuel capacity including solar, biogas and geothermal energy. In this study, a numerical investigation of the effect of a circular, pin, and rectangular fins on the performance of the Stirling engine is introduced. The 3D CFD model was performed and validated with previous experimental study. The power output, heat transfer rate and efficiency were studied for all cases of fins. The results indicated a close agreement between the numerical and the experimental results with average difference for power of the engine approximately around 2.8%. The efficiency decrease with the increase of the rotational speed of the engine and the highest efficiency is indicated for rectangular fins.