Stirlingengineforum.com

Tom Booth wrote: ↑Sat May 30, 2020 8:30 am "That does seem rather remarkable, that an engine hot enough to melt solder, nevertheless, did not burn or char the balsa wood displacer."

It surprised me too, the most dramatic desoldering occured on the fire box with the chimney sliding off the roof. Having failed with the silver solder I have reassembled the firebox with mechanical joints, clamp arrangements and fire gum paste all of which seems to have been succesfull. When the retail facilities reopen after the shutdown I will change out the bushing for the push rod to a drilled brass screw. This will illiminate all soldered joints from the heated zone.

Tom Booth wrote: ↑Sat May 30, 2020 8:30 am Currently I'm trying some of that rigid foam used for craft, I think mainly for flower arrangements. I'm not at all sure how well that could take heat, but right now I'm experimenting with a cold running engine."

Good luck with the flower arranging foam, I hope you have better success than me. Maybe there are different types or grades but what I had was very crumbly and my large thumbs could not cope with it.

Tom Booth wrote: ↑Sat May 30, 2020 8:30 am "I'm always curious regarding the question of using a displacer vs. regenerator (or "regenerative displacer"). I've seen evidence that using a regenerator makes a big difference, but then I've also read accounts where someone experimented with both and found no advantage to using a regenerator."

I am slowly starting to get my head around what a regenerator is and I may try one in the future if I have no other projects. At the moment I am working on an electrical generator and would like to build a pump, the lockdown is restricting access to materials and slowing progress, I have ordered some bits and pieces from China so I will wait and see which is available first.

Once the lockdown restictions are lifted then I may have access to materials, but at that point I am sure my wifes list of essential jobs will reappear. You cannot win.

Toodlepip

Probably the easiest way to understand how a regenerator works is to start with an ordinary displacer.

The displacer forces air from the hot to cold side of the engine and back.

If, instead of a solid displacer, holes were drilled through the displacer and the holes stuffed with steel wool, now the air flows back and forth through the steel wool.

The steel wool will trap heat as the hot air flows through in one direction and then give heat back as cold air flows back through the steel wool in the other direction.

The image shows an ordinary displacer modified to include some holes filled with steel wool.

The experimentor on this website relates that this modification results in a considerable improvement in engine performance.

http://www.solarheatengines.com/2008/06 ... generator/

To quote, the author states: "If you test your engine without the regenerator and then add it, you’ll probably be as blown away as I was that 0.6 grams of steel wool (this is almost nothing) can make such a huge difference."

Your engines are some of the most beautiful works of "kinetic art" I've seen in a long time. Very impressive. Thank you again for sharing.

Tom

Make the concept work?

I did very close to this maybe 10 years ago! LOL
Except mine was water cooled.

https://boydhouse.com/stirling/horizontal/index.html




Darryl Boyd