Stirlingengineforum.com

Far from being a curiosity, in my solar engine, the water vapor condenses in the power cylinder and will slow it down and then stop it. Have you tried using silica gel (or other dessicant) to dry your air? It doesn't need to be pressurised to do this, you just need a decent seal to ensure that the ...

If it helps, bear in mind that some commercial Stirlings use Hydrogen or Helium as the working gas, so no mixture or water vapour effects. As far as I know, these are more efficient, but don't work substantially differently from air-based engines.

Tom, I see you mention "molecular attraction" again - I'm not aware that any common gas has this property; indeed I was under the impression that a truly un-constrained gas would expand to fill whatever container it is in, regardless of temperature and pressure. Maybe I'm misunderstanding ...

"Why do these various engines have heavy weights on the diaphragm "pistons"?" I suspect the main reason is that the engine is at atmospheric pressure inside, at rest. Once the engine has been 'fired up' the internal pressure will rise substantially. For a diaphragm-based engine i...

I quite agree with Tom: the mass of a piston is directly _ counter _ to the ideal operation of _ any _ engine - a massless piston is always going to be better overall than a heavy one.

To be positive for once - you don't need to measure temperature - you have a known (though not entirely fixed) volume of gas, so if you are able to measure the pressure then you can calculate the temperature from that. Whether pressure sensors are significantly faster than temperature sensors I have...

That video of adiabatic bounce is quite a clever demonstration, but I have to point out: As you note, no REAL work is done - in our nice, perfect frictionless theoretical world, the 'piston' will continue to oscillate perpetually. But without doing any work, which is the fundamental point of any eng...

Water is not energy, only a carrier of gravitational energy. The bottom video shows that that particular water wheel is rather inefficient since much of the water is being thrown clear. My problem with the experiment you describe above is that heat transfer is happening in three phases, not one: Fla...

If you want to know more about how that works, look up "Parallel Motion" which was used on steam engines long before Stirling came along.

Gary, sealing is actually one of the advantages of using a double-acting power piston - any leakage past the piston itself goes into the other half of the engine, rather than being vented, and then presumably leaks straight back the other way after 180 degrees. Sealing the various con-rods is an inh...

How was that 40% calculated / measured?

Most of us are used to _ slightly _ lower numbers than that...

Pretty much everything is inter-dependant: materials; temperature difference; power; speed

Those numbers don't look very different to what I would expect for modern power-producing machines - LTD models are at the opposite end of the spectrum due to that pesky "Low" in the name.

"It is well know that it takes TIME to transfer heat by conduction" Yes, that is one of the real-world compromises that we face - the longer we have for heat/energy transfer (in either direction) the more will transfer, but even at zero RPM the air on the inside will never reach the temper...

The energy introduced as heat is "let out" as mechanical "work". This is what I was trying to get at with the wind-turbine analogy - you missed out the word "some" above - _some_ of the energy in the air inside the engine gets transferred to work done by moving the pis...

I was once told that "All models are wrong, but some are still useful." The Carnot idea of heat as a fluid is a useful concept most of the time, but I don't think I've ever seen anyone suggest that it can be 'intercepted'. Similarly many of these conversations try to cover too much ground,...