Stirlingengineforum.com

Has anyone here made their own custom diaphragm by layering fabric and rtv or plain silicone? It'd be nice to be able to make the exact shape and weave-strength orientation you want. You could even cast in some metallic portions. Any tips?

Ian, the displacer won't hit the sides. The limited amount of rocking is a factor of how long the rod vs. how short the displacer, relative to the effective pivot point. I do admit though, to having difficulties getting enough diaphragm flexibility while maintaining enough lateral strength. I could ...

Hi Alex. I'm working on electricity from a woodstove too. My seal is sort of "elegant," but I've no idea yet if it will work. My displacer design uses a short stroke so the rod can move with a diaphragm, which also allows it to rock a little bit so there are no extra joints needed in the r...

Hi Tom. I didn't know that about Tesla. Good company indeed. I don't know if I understand you to mean that you could collect energy by simply exhausting the cold gas - the temp drop doesn't represent power until it collects ambient heat, a process that would in that case happen externally and be tot...

Thanks Ian, that’s what I was thinking, but couldn't see it that clearly. Looking at it as the same heat pump, whether it's driving or driven, helps visualize. It would seem then, that if you throttle an engine by using variable displacer timing, if you took it far enough you could have a regenerati...

With consistent direction of rotation, which end of a Stirling gets hot when it's powered as a heat pump instead of making power as an engine? I'm thinking it would be the same as an electrical motor/generator situation where the polarity is the same, but the more I think, the less sure I am. I'm ju...

Thank-you both. I've taken my own thread off topic. I'd still like to hear anyone's other suggestions for insulation. I thought about expanding foam, but that's probably not a good idea in a hot chamber. Currently, the partition idea seems most likely, but difficult.

Ian, I admit I have little experience and a lot to prove, but I don't think there could ever be one ideal displacer shape. If I were to scale down to a 7" long by 3" dia. displacer, it would roughly match your ratio, but would still only have the same regenerating length as what I already ...

Ian, thanks for responding. My list of compromises is already long and I don't want to add more than I have to. Isolation instead of insulation is a good idea, it's just that I already welded up my displacer before realizing the problem. It's a small air-compressor tank cut to length, with one end i...

Hi. New guy here, glad to find folks of like interest. Does anybody insulate the inside of hollow displacers? I think the air flinging about in there would carry a lot of heat to the cold end. Convection inside a long narrow displacer wouldn't be as severe, but mine is 12" dia. X 7". Are t...