Nice to see this posted. I spent probably too much time on Stirling engines and associated stuff (heat engines in general, the Vuilleumier family of devices and other interesting bits & pieces). It's so tempting, you think there has to be a way to make it work. But I haven't found one yet and I more or less gave up on it. The most practical ones that I'm aware of are in spacecraft for extreme cooling and in a commerc…
Stirling engines are a perfect illustration of what I call Odum's Paradox: The closer a heat engine/pump gets to maximum theoretical efficiency, the lower its power density. This is a simple consequence of thermodynamics. By approaching the Carnot efficiency you're asymptotically approaching an adiabatic cycle, so there's less and less entropy gain to drive the system forward. At the Carnot efficiency the cycle becom…
Re: Stirling Cycle Machine Analysis
#11Yes! There is a similar thing happening in windmills that leads to Betz' law, if a windmill were to extract all energy in the wind it wouldn't work because the air has no place to go to behind the machine. In order to do meaningful extraction of energy you simply have to accept a minimum amount of loss, attempting to increase that fraction will increase the losses, not decrease them.