Abstract
The method to evaluate the effect of regenerator efficiency on an indicated work of low temperature differential Stirling engine is proposed. The method enables to estimate the ensemble averaged temperatures and temperatures at the outlet of the regenerator in both hot side and cold side of displacer chamber. The estimation requires assuming the surface temperatures of both sides heat exchanger, the ratio between the difference between regenerator outlet temperature and heat exchanger temperature and the difference between ensemble averaged temperature and regenerator outlet temperature, and regenerator efficiency. The abovementioned ratio caused by three temperatures can estimate by two-dimensional steady-state CFD, and is about 0.3 in case of conventional low temperature differential Stirling engine. Obtained ensemble averaged temperatures will cause an indicated work by isothermal model calculation, and regenerator efficiency will affect on the calculation result. Although the empirical method to estimate regenerator efficiency has been proposed, much inexpensive method for engineering education or hobby should be proposed as next step.
