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Something I would Love to see

Posted: Fri Mar 19, 2010 2:13 pm
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.

Re: Something I would Love to see

Posted: Fri Jul 09, 2010 7:20 pm
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

Re: Something I would Love to see

Posted: Tue Jan 13, 2015 11:04 am
by Tom Booth
From Wiki Creative Commons image
From Wiki Creative Commons image
220px-Schlieren-color-candle-plume.jpg (9.65 KiB) Viewed 4579 times
Thanks!!!

Looks like that should be possible as a DIY project.

Schlieren Photography - How Does It Work?

Re: Something I would Love to see

Posted: Fri Jan 16, 2015 10:32 am
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.

Re: Something I would Love to see

Posted: Tue Jan 20, 2015 4:51 am
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.