Stirlingengineforum.com

With the long tube to power piston I'd bet it would have a better chance at running from heat of hand if the top side was the hot side.

Seems like a good choice for cold bottom and ambient top side.

36.5j for free expansion to 200cc at 600k.

Now how would we calculate additional heat input for the 102g piston in your first example?

It looks like I goofed my earlier calc by a factor of 10, so it's 36.5J, not 3.65. In the more complex case of joules needed at constant volume, a reasonable engineering approximation would be to multiply the Cv value of air by the mass of air and the change in Temperature. 0.718 x 0.12g x 300 = 25...

I have since watched the video. Seems plausible. They make no claims for BTU output, just a temperature reduction. There is certainly an orifice.

I guess one would have to recreate the test to verify.

Yes. This is what Charles law tells us: "When the pressure on a sample of a dry gas is held constant, the Kelvin temperature and the volume will be in direct proportion." Hence: V1/T1 = V2/T2 The equation shows that, as absolute (Kelvin) temperature increases, the volume of the gas also i...

Stroller can answer other questions as he sees fit, but I would like to focus on the very basics for a moment. I'll chime back in after I get home today.

Thanks Mike, I phrased my post badly. 3.65J would double the volume of freely expanding air. But the air has to expand against the force of gravity acting on the 102g piston mass, which is where we use the extra 1J to lift it 1m. So, as you said, that's an extra Joule for 4.65 total. Putting the we...

Stroller, thanks for your time here. I'll let you sort out MikeB's excellent comment before I chime in. I'd say he's barking up the right tree.

I see, I haven't watched either.

Tom can you unpack that? How would it work without an orifice?

I don't follow baseball but I guess you're from across the pond then?

For starters, I'd like to see a test conducted that proves actual destruction of heat. Not a reduction of, say, internal energy per cubic centimeter, but actual destruction/ conversion of heat energy.

I meant internal pressure and buffer pressure. How do you increase internal pressure without raising buffer pressure too?

An ICE uses a turbo or supercharger to trade some shaft or exhaust power for an even greater gain in specific output with extra fuel.

What would be the equivalent "supercharging" for a Stirling engine? Just a buffer pressure boost? Or something temperature related?

I think what is hard to digest is that the 14.7psi atmospheric return stroke helps a typical gas ECE as much as it does an atmospheric Stirling engine. It's just that the atmospheric pressure adds a significant level of power to the Stirling engine, due to its low output on expansion, whereas the sa...

Here's my contention with the absolute zero thing, the best we can do on earth is exhaust down to 1atm at 300k or so. So chasing "100%" efficiency is like a baseball player chasing a 1.0 batting average, when .300 is considered excellent, and .400 is unheard. Instead, re-framing "100%...