can a laminar flow stirling engine do real work
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stirlingengine123
- Posts: 5
- Joined: Sun Mar 22, 2015 7:32 am
can a laminar flow stirling engine do real work
on youtube i have seen many laminar flow stirling engines which use one piston but most of them dont do any real work they are really just toy models. but i have wondered if these can be scaled up to produce lets say at least 100 watts i have seen only about two on youtube which generate over 10 watts. anyway i noticed the larger lamina flow engines on youtube`used an inner pipe inside the heat tube but i didnt understand how it works so if anyone knows how to build one that produces real power please leave a comment also i wondered if laminar flow engines work as a heat pump in reverse
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Aviator168
- Posts: 308
- Joined: Tue Feb 08, 2011 2:29 pm
- Location: Brokeville, NY. USA
Re: can a laminar flow stirling engine do real work
Find a design that works and make improvements. I asked the same questions and finally just built my own to find out. Yes they can do work but 100 watts is a lot for any home built heat engine. Here are the plans for my engine. Not extremely detailed but good enough to get started. As far as your question about the inner tube. The inner tube is open on the hot end, it reduces dead volume between the cylinder and the hot end without reducing overall volume.
http://www.mediafire.com/download/hdbcb ... _plans.zip
https://youtu.be/wtW9fYVFXOY
http://www.mediafire.com/download/hdbcb ... _plans.zip
https://youtu.be/wtW9fYVFXOY
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Aviator168
- Posts: 308
- Joined: Tue Feb 08, 2011 2:29 pm
- Location: Brokeville, NY. USA
Re: can a laminar flow stirling engine do real work
Same issue as other stirling engine. Problem with getting a lot of great in and out
Re: can a laminar flow stirling engine do real work
It helps to know what is actually going on inside one of these engines.
After running my laminar flow, thermoacoustic, thermal lag, or whatever irs supposed to be engine, with the "inner tube" as its being refered to here made of wood.
The wood sometimes, after the engine has run for a while starts to smoke.
Pretty obviously that passageway is being subject to some very high temperatures.
This will rather quickly cause the engine to stall. The smoke and wood resin gums up the piston and cylinder like chewing gum, then it will have to be cleaned.
The extreme heat also tends to degrade the silicone O rings.
With all that, however, the power piston stays cool. Even after running several minutes with a styrofoam sleeve covering the power piston, it has never become hot to the touch, not even warn really.
Anyway, what was interesting about the passage through the wood starting to smoke and the engine stalling is that it provided a very clear view of the air flow out of the orifice.
Unfortunately, by the time I noticed this and grabbed my phone the smoke was already starting to clear so it cannot be seen as clearly in the video, but it was most definitely a long smooth laminar flow streaming straight into the steel wool.
https://youtu.be/Yt5CYSXK3A8?si=OE8E2VtT75hQ5vS3
I would need to do more testing to be sure, but experimenting a little, the laminar flow extends into the hot cylinder only so far before breaking up.
Progressively shortening the steel wool, I had a difficult time trying to start the engine if the steel wool was too far for the laminar stream to reach.
I'd have to assume that a similar stream flows out from the opposite end of the orifice.
After running my laminar flow, thermoacoustic, thermal lag, or whatever irs supposed to be engine, with the "inner tube" as its being refered to here made of wood.
The wood sometimes, after the engine has run for a while starts to smoke.
Pretty obviously that passageway is being subject to some very high temperatures.
This will rather quickly cause the engine to stall. The smoke and wood resin gums up the piston and cylinder like chewing gum, then it will have to be cleaned.
The extreme heat also tends to degrade the silicone O rings.
With all that, however, the power piston stays cool. Even after running several minutes with a styrofoam sleeve covering the power piston, it has never become hot to the touch, not even warn really.
Anyway, what was interesting about the passage through the wood starting to smoke and the engine stalling is that it provided a very clear view of the air flow out of the orifice.
Unfortunately, by the time I noticed this and grabbed my phone the smoke was already starting to clear so it cannot be seen as clearly in the video, but it was most definitely a long smooth laminar flow streaming straight into the steel wool.
https://youtu.be/Yt5CYSXK3A8?si=OE8E2VtT75hQ5vS3
I would need to do more testing to be sure, but experimenting a little, the laminar flow extends into the hot cylinder only so far before breaking up.
Progressively shortening the steel wool, I had a difficult time trying to start the engine if the steel wool was too far for the laminar stream to reach.
I'd have to assume that a similar stream flows out from the opposite end of the orifice.
Re: can a laminar flow stirling engine do real work
Needless to say, with such a strong stream of air passing back and forth between the power cylinder and the hot cylinder I see no chance whatsoever of any kind of "standing wave" establishing itself in there.