Search found 27 matches

by tenbitcomb
Thu Nov 17, 2022 6:56 pm
Forum: Stirling and "Hot Air" Engine Forum
Topic: Absurdly simple thermoacoustic-steam "rice" engine – What's going on here?
Replies: 136
Views: 47974

Re: Absurdly simple thermoacoustic-steam "rice" engine – What's going on here?

My old steam thermoacoustic engine: https://1.bp.blogspot.com/-5Ua7opwlOfU/YKsJKwA2rQI/AAAAAAAAFng/lmK9FbA347E-5Ia9Im9Za_1WTjiYOg4AwCPcBGAsYHg/s320/egyszeru.jpg , https://1.bp.blogspot.com/-R_PUDw4Kpi8/YKsJYSfJZ5I/AAAAAAAAFnk/usEcBOSgfSYg3H8of4yXGAIaCkqHXuUMgCPcBGAsYHg/s320/IMG_0003.JPG an experime...
by tenbitcomb
Thu Nov 17, 2022 6:41 pm
Forum: Stirling and "Hot Air" Engine Forum
Topic: Absurdly simple thermoacoustic-steam "rice" engine – What's going on here?
Replies: 136
Views: 47974

Re: Absurdly simple thermoacoustic-steam "rice" engine – What's going on here?

I get the idea of compression and expansion with phase change, but the significance of any "acoustic" element escapes me. The term "acoustics" is somewhat of a misdirection. Acoustics are merely kinetic wave dynamics, and that may or may not have anything to do with audible soun...
by tenbitcomb
Thu Nov 17, 2022 1:52 pm
Forum: Stirling and "Hot Air" Engine Forum
Topic: Absurdly simple thermoacoustic-steam "rice" engine – What's going on here?
Replies: 136
Views: 47974

Re: Absurdly simple thermoacoustic-steam "rice" engine – What's going on here?

I'd share a link to the full version of that paper, but I hesitate to do so since it sounds like Daemon's original account and posts were wiped, and he was the one who originally shared it. I don't want to suddenly disappear because of sharing something like that in case that's what happened. Howeve...
by tenbitcomb
Wed Nov 16, 2022 1:44 pm
Forum: Stirling and "Hot Air" Engine Forum
Topic: Absurdly simple thermoacoustic-steam "rice" engine – What's going on here?
Replies: 136
Views: 47974

Re: Absurdly simple thermoacoustic-steam "rice" engine – What's going on here?

Yeah sure, I'm on vacation over seas atm, but I'm taking some time to work on it. I've got a mill, lathe and a few engineers from Siemens here interested in helping me get a piston model running. So I'll probably have some great insights to post to my channel next week. Awesome! I recently tried us...
by tenbitcomb
Wed Nov 16, 2022 1:39 pm
Forum: Stirling and "Hot Air" Engine Forum
Topic: Absurdly simple thermoacoustic-steam "rice" engine – What's going on here?
Replies: 136
Views: 47974

Re: Absurdly simple thermoacoustic-steam "rice" engine – What's going on here?

> Trichlorofluoromethane R-11 refrigerant One problem that almost any alternative fluid introduces is the need to always keep the engine totally sealed, given that these fluids are usually either poisonous or flammable or both. The nice thing about water is it's plentiful and nontoxic, therefore it ...
by tenbitcomb
Wed Nov 16, 2022 1:28 pm
Forum: Stirling and "Hot Air" Engine Forum
Topic: Absurdly simple thermoacoustic-steam "rice" engine – What's going on here?
Replies: 136
Views: 47974

Re: Absurdly simple thermoacoustic-steam "rice" engine – What's going on here?

My guess is Tristan's engine isn't thermoacoustic but is actually an alpha Stirling engine. Here's the video where he shows the internal workings: https://www.youtube.com/watch?v=CXsFNPmjluo (curse YouTube for continuing to make finding old videos an incredible pain) I don't know why he called it a ...
by tenbitcomb
Tue Nov 15, 2022 2:15 pm
Forum: Stirling and "Hot Air" Engine Forum
Topic: Absurdly simple thermoacoustic-steam "rice" engine – What's going on here?
Replies: 136
Views: 47974

Re: Absurdly simple thermoacoustic-steam "rice" engine – What's going on here?

> Is it concussion from steam explosions? I don't think so. The engine will continue running despite a lack of boiling once it's been removed from the heat. In my experience, it may do this anywhere from 10 seconds to even a minute. Honestly, I think the boiling and steam flashes are a red herring. ...
by tenbitcomb
Sun Oct 23, 2022 12:07 pm
Forum: Stirling and "Hot Air" Engine Forum
Topic: Absurdly simple thermoacoustic-steam "rice" engine – What's going on here?
Replies: 136
Views: 47974

Re: Absurdly simple thermoacoustic-steam "rice" engine – What's going on here?

I've now confirmed that it's absolutely feasible to run the engine continuously for at least an hour, and likely much more so. As I think I've already mentioned, the key is really about maintaining a balance between the input and the output. An external combustion engine shouldn't really be that dif...
by tenbitcomb
Sun Oct 23, 2022 9:49 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: Absurdly simple thermoacoustic-steam "rice" engine – What's going on here?
Replies: 136
Views: 47974

Re: Absurdly simple thermoacoustic-steam "rice" engine – What's going on here?

I had some modest success with a diaphragm made of parchment paper. Sounds just like a two-stroke!

https://www.youtube.com/watch?v=T_-j91E6CCQ
by tenbitcomb
Sun Oct 23, 2022 6:35 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: Absurdly simple thermoacoustic-steam "rice" engine – What's going on here?
Replies: 136
Views: 47974

Re: Absurdly simple thermoacoustic-steam "rice" engine – What's going on here?

I really need to get a needle-syringe and try the flash boil approach. It makes me wonder if the engine could benefit from a "carburetor" of sorts that sprays small amounts of water into the boiler as a result of the fluctuating pressure.
by tenbitcomb
Sun Oct 23, 2022 6:33 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: Absurdly simple thermoacoustic-steam "rice" engine – What's going on here?
Replies: 136
Views: 47974

Re: Absurdly simple thermoacoustic-steam "rice" engine – What's going on here?

Something I would like to point out though, this engine produces a lot of power with very little heat when you have everything tuned in correctly. At one point I started the engine with 3 tea lights, which overpowered it realy fast, so I had to run it with 2 tea lights and even then I had to be car...
by tenbitcomb
Fri Oct 21, 2022 11:14 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: Absurdly simple thermoacoustic-steam "rice" engine – What's going on here?
Replies: 136
Views: 47974

Re: Absurdly simple thermoacoustic-steam "rice" engine – What's going on here?

Oh yeah, so there's a few things I want to hopefully get to testing out this weekend. Building a clear version of this engine might be helpful in visualizing what's going on. I'm thinking I want to give my hand a try at cutting some glass cylinders out of wine bottles and see how that goes. If I can...
by tenbitcomb
Fri Oct 21, 2022 11:03 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: Absurdly simple thermoacoustic-steam "rice" engine – What's going on here?
Replies: 136
Views: 47974

Re: Absurdly simple thermoacoustic-steam "rice" engine – What's going on here?

Yep Tom, you're right on the money. There's a kind of tradeoff and balancing act going on here between efficiency and how long the engine can operate at a given rate of heat transfer. The engine doesn't necessarily need to be cooled, nor is that cooling necessarily a good thing for fundamental opera...
by tenbitcomb
Thu Oct 20, 2022 7:41 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: Absurdly simple thermoacoustic-steam "rice" engine – What's going on here?
Replies: 136
Views: 47974

Re: Absurdly simple thermoacoustic-steam "rice" engine – What's going on here?

@Tom Booth Interesting findings around the Leidenfrost effect! In a weird coincidence, I was actually saved from a burn a couple of days ago by the Leidenfrost effect when working on this engine. My hand was dripping wet from the sink and the back of my hand lightly touched a very hot surface, but a...
by tenbitcomb
Wed Oct 19, 2022 3:44 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: Absurdly simple thermoacoustic-steam "rice" engine – What's going on here?
Replies: 136
Views: 47974

Re: Absurdly simple thermoacoustic-steam "rice" engine – What's going on here?

Very nice! The engine does seem to need to be kicked off before it can be sustained with lower power. I've been able to keep mine running indefinitely with a mini butane torch lighter. Also, I tried swapping out the rice with aquarium gravel and it works quite nicely. I think I'll be using that from...