Something I would Love to see

Discussion on Stirling or "hot air" engines (all types)
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Tom Booth
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Something I would Love to see

Post by Tom Booth »

I think it might be very educational; informative; interesting etc. and possibly serve to dispel (or validate ?) some of the "Myths" or theories surrounding the actual workings of a Laminar flow Stirling engine if someone with the means to do so would blow some smoke - or possibly put some very fine dust (like talcum powder) into the cylinder of one of these test tube engines and video tape it running.

Or better yet, use a high speed camera so it can be viewed in slow motion.

In this way the air movement could be seen.

If there are any acoustic or other kind of "standing waves" or "compression waves" generated these should show up as the smoke particles or dust would tend to accumulate at the various nodal points, (3D Chladni patterns) much as when sand is scattered over a violin and accumulates at the nodal points:

http://www.phys.unsw.edu.au/jw/chladni.html

Otherwise, it might just be shown that the gas simply expands and contracts back and forth through the "choke" in an ordinary flow or stream. The smoke or dust would make this movement, whatever it may be, visible.
Murph
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Re: Something I would Love to see

Post by Murph »

You would have to use Schlieren photography to see the gas flow inside the engine.

http://en.wikipedia.org/wiki/Schlieren_photography

Anything that you can see, chalk, smoke, whatever--would act as an abrasive and impede the engine's gas flow and operation, and would settle out when the engine was nor running.

Murph
Tom Booth
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Re: Something I would Love to see

Post by Tom Booth »

From Wiki Creative Commons image
From Wiki Creative Commons image
220px-Schlieren-color-candle-plume.jpg (9.65 KiB) Viewed 4578 times
Thanks!!!

Looks like that should be possible as a DIY project.

Schlieren Photography - How Does It Work?
Aviator168
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Re: Something I would Love to see

Post by Aviator168 »

It would be more interesting to see the same thing on an alpha stirling. See the location pressure builds up where it shouldn't be or the speed of the gas when it goes through the transfer tube.
Tom Booth
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Re: Something I would Love to see

Post by Tom Booth »

Aviator168 wrote:It would be more interesting to see the same thing on an alpha stirling. See the location pressure builds up where it shouldn't be or the speed of the gas when it goes through the transfer tube.
Yes, or how much heat the regenerator is absorbing and releasing... I suppose whatever engine would need to be transparent though in any case.
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