Numerical modeling and optimization of beta-type Stirling engine

Numerical modelling can significantly contribute to the performance enhancement and technological advancement of Stirling engines. In this paper, a practically feasible thermodynamic model was developed for beta type of Stirling engines with rhombic-drive mechanism. Quasi-steady flow approach was adopted to analyze the heat transfer and flow friction effects of the heater, cooler, and regenerator on the performance of engine. The numerical model predicts the output power and thermal efficiency while considering the pressure drop in heat exchangers and numerous power and thermal losses. A parametric study is utilized to investigate the impact of operating and geometric parameters on the power output and efficiency of the Stirling engine. A combination of optimized temperature ratio, swept volume, regenerator matrix porosity, phase angle, pressure and engine frequency are assessed. The optimized model is then compared and validated against the experimental data obtained from the General Motor's prototype of GPU-3 Stirling engine. Substantial improvement on the performance of the engine is achieved by optimizing the operating and geometric parameters of the engine.