Development of a beta-type Stirling engine with rhombic-drive mechanism using a modified non-ideal adiabatic model

The aim of this study is to develop an efficient theoretical model that can more accurately predict the performance of the designed engine. The developed model is practically further applied in the development of a 500-W engine. The theoretical model is built by modifying the existing non-ideal adiabatic analysis to more accurately predict performance the designed engine. In this model, pressure drops in the heater, the regenerator and the cooler caused by fluid friction, channel sudden expansion and sudden contraction are taken into consideration. Furthermore, an empirical formula for the mechanical loss as a function of rotation speed of the engine is obtained by experiments and introduced into the model. The shaft power, indicated power, and thermal efficiency of the engine are determined. Furthermore, a prototype engine is then built and tested to validate the model. Experimental measurements on the power output are conducted in this study. It is found that maximum shaft power of the prototype engine can reach 556 W at rotation speed of 1665 rpm and at a heating temperature of 1100 K.