Stirlingengineforum.com

Has anyone measured the power output of a small Stirling, either with a brake dump or figuring out the flywheel moment of inertia and the angular acceleration? I cobbled together a very crude setup with a tachometer, a pad rubbing against a flywheel and some kitchen scales, and derived a power outpu...

An interesting point that perhaps got missed in the video was the engine running on after the heat source was gone- there’s quite a lot of thermal mass in that little engine that needs to be “charged”- and my educated guess is that’s why you won’t get instant starting... and why Stirling Engines are...

Thanks for the replies, although I would be a little bit skeptical about having to spin engines before they start running on their own. I would have my doubts that this is anything to do with the Stirling Engine operating principle, and more to do with thermal lag and bearings warming up. If there's...

On the first test with the heat applied.... it wouldn’t keep running beyond one cycle- I would have thought that if it’s ever going to work, it should just need a quick nudge to get it out of a dead spot, after that, it’s on it’s own. I could tell *something* was happening- it was harder to crank ba...

With the first attempt with a diaphragm, and a much shorter coupling tube, it wouldn't keep running- my guess is that the force produced under that configuration wouldn't overcome the frictional losses. I think, though, that I'm onto something with the water manometer. The displacer was pretty crude...

*** Can I/how do I embed videos in a post?*** I've made a bit of progress with a long running project, based round discarded Nitrous Oxide bottles. Basically, kids buy full bottles here in the UK for £20-£30, drive to a layby, have a party, and discard a nice chunk of thick walled tube, 70mm diamete...

Thanks for the reply- just to give a little bit more context, my heat source is going to be the -currently- wasted heat from my biochar making burners. I've currently got more heat than I know what to do with, by "heat", I mean hot flowing gas, and getting it transferred into the hot end i...

https://www.sciencedirect.com/topics/engineering/stirling-cycle I think the answer that I'm looking for is the equation: energy per cycle=(mass of air in play)*(gas constant for air)*(temperature difference)*ln(compression ratio) so, putting in values of 0.0005 kilos of air, 319.3 for the gas consta...

I've been figuring out in my head how regenerators work, what they do, and what they don't do. Do I understand correctly, that they work by storing and releasing some of the heat energy, so that the engine takes smaller "bites" of heat per cycle? So they improve the efficiency, with a smal...

If you Google for "Pain Mound", that's the go-to technology for extracting heat from compost, but you really need to think in terms of large volumes- the power density of a compost heap is only about 250 Watts per cubic metre.

Thanks for the reply- do I understand... that there's around 2 Joules per revolution given the swept displacer volume and temperature difference? How do you calculate that? I do realise that it's a theoretical upper limit, but I can see 10 Watts to charge a phone within reach. Could you bring me up ...

Thanks for the reply- what I've got in mind is going to be fairly modular so that I can experiment. I want to see if I can incorporate a condom as the diaphragm :-)

....has anyone tried it? I'm talking about a semicircular cross section displacer rotating in a cylinder with the hot source on one side and the cold sink on the other? It won't match anything with a regenerator for efficiency, but it will eliminate a lot of the reciprocating mass.

Is there an accepted formula for what power output to hope for given the engine RPM, displacer bore and stroke, and temperature difference? The engine under construction is working between an estimated 300 and 600 Kelvin, with a displacer 65mm diameter and 120mm stroke, running on air without pressu...