Fabrication and test of gamma-type Stirling engine

In this investigation, a gamma-configuration Stirling engine is designed and constructed. The single and twin power cylinder engines are tested with air at atmospheric pressure by using an electric heater as a heat source. The engine is tested with heater input of 156.3W, 187.6W, and 223.2W. Variations of engine torque, shaft power and brake thermal efficiency with engine speed and engine performance at various heat inputs are presented. The results indicate that at the maximum heater input of 223.2 W, the heater temperature for single power cylinder and twin power cylinder are 612°C and 574°C. The two engines produce a maximum torque of 0.13 Nm at 405 rpm and 0.15 Nm at 412 rpm; a maximum shaft power of 5.73 W at 456 rpm and 6.47 W at 412 rpm; a maximum brake thermal efficiency of 2.57 % at 456 rpm and 2.9 % at 412 rpm, respectively.