Numerical and experimental study of a compact 100-W-class β-type Stirling engine

The study aims to present a three-dimensional CFD model for simulating the physical phenomena in a compact 100-W beta-type Stirling engine. The thermal efficiency and the indicated power can be further computed based on numerical predictions. The effects of some influential parameters on the engine performance have been carried out through a parametric study around a chosen baseline case. In parallel, a prototype engine is built for testing. Experiments are conducted to obtain the shaft power. The mechanical power loss dependent on the rotation speed, and the heating temperature is evaluated based on the numerical and experimental data. The engine can reach up to 87.2 W at the 1350 rpm rotation speed. The maximum thermal efficiency is 41.9% at the 10 bar charged pressure while the power can be significantly raised to 507.3 W at the 15 bar charged pressure. As the heating temperature is lifted between 673 and 1173 K, the power raises from 30.3 to 111.5 W and the thermal efficiency goes up from 13.3% to 42.3%. As the cooling temperature is raised from 200 to 350 K, the power decreases from 138.3 W to 65.3 W and the thermal efficiency falls from 47.3% to 28.2%. An increase in the piston length from 49.5 to 61.5 mm lifts the power from 61.8 to 85.9 W, while the thermal efficiency reaches a peak of 35.1% at 58.5 mm.