So far, to improve the Stirling engines performance the research
was focused on the development of the mechanical transmission
system [10] and on the gas circuit performance [11]. In particular
looking for driver mechanism to minimise mechanical losses and
heat exchanger geometry to reduce pressure losses and improve
heat exchange. The choice of working fluids is at present limited to
helium, hydrogen and air (nitrogen).
the reduction in useful power, caused by the increase in pressure
losses, which are proportional to the rotation speed.