Stirlingengineforum.com

Tom Booth wrote: ↑Thu Dec 07, 2023 7:19 am What would the "regenerator" consist of?

It appears (upper right) to reduce to zero volume.

It does. The remaining hot/warm air in it will be used in the cold cylinder.
It is another rotor of the same size as the other two. I don't think it's a regenerator as we know in other engines, but it separates fluid and moves it around to be reused while keeping the temperature in it.

Fool wrote: ↑Thu Dec 07, 2023 7:34 am Jack, are you striving for a first ever pseudo-Carnot cycle?That's what it looks like. Excellent.

It didn't start like that, but along the way I realized it comes very close to one. I'm hoping it works as planned haha.

I'm starting to think I shouldn't open the green port to all cylinders, but limit it between hot and cold. That way I get a higher delta t in the hot side and the fluid in the regenerator doesn't mix with cold fluid so it puts out work more efficiently when it gets to the cold cylinder.

Any inspiration to be drawn from this paper, which describes a dual vaned rotor Stirling engine and has a downloadable full pdf that includes some potentially useful design details, such as block shapes, ports, etc.
https://www.researchgate.net/publicatio ... hitecture

Yeah I found that one. Great info!

I'm stuck. I imagine it's a common problem with these engines. I'm thinking myself in circles. Every time I get to grip with a new concept I think I find a "weakness", try to solve that and end up with a previous concept.

My search has turned from trying to find a way to make power from our stove, to trying to find the most efficient engine.

So I've started asking myself a different question. What do I need for this to be the most it can be?
I don't know how much heat input I can get from the fire. I can guess, but I could be way off.

Because I don't know that, I can't really tell how much displacement I should aim for.
So is the solution to that an engine with adjustable displacement? And how can I achieve that?

Another day, another problem. Does this ever end? Haha

The universe provides.. down another rabbit hole we go..

A reverse image search turned up this article:

https://www.tomorrowstechnician.com/var ... oil-pumps/

Jack wrote: ↑Mon Dec 11, 2023 10:08 pm I'm stuck. I imagine it's a common problem with these engines. I'm thinking myself in circles. Every time I get to grip with a new concept I think I find a "weakness", try to solve that and end up with a previous concept.

My search has turned from trying to find a way to make power from our stove, to trying to find the most efficient engine.

So I've started asking myself a different question. What do I need for this to be the most it can be?
I don't know how much heat input I can get from the fire. I can guess, but I could be way off.

Because I don't know that, I can't really tell how much displacement I should aim for.
So is the solution to that an engine with adjustable displacement? And how can I achieve that?

Another day, another problem. Does this ever end? Haha

Why don't you measure it? You mentioned stove and fire, while I don't know what your stove looks like, maybe you could measure how much time it takes it to bring up the temperature of a known mass of water. All you would need is a good way to measure the mass of water, its temperature and of course a stopwatch.

That's an idea, yeah. Hadn't thought of that. Thanks.

After getting myself in a mental loop of efficiency and solutions I had to take a little step back and try to see what was really important.
I've got one rotor here that I'll turn into a single rotor prototype. So I'll heat up one side of the cylinder and cool the other. Just to see if this concept could work.

Another thing I want to try is a brayton or Ericsson engine. With two rotors, one compressor and one turbine. Usually this needs valves to work. But I want to try to make the hot reservoir out of tesla valves. No idea if it can work, but worth a try.
I found this video and I'm guessing it will work kind of similar with a hot air engine.
Tesla valve with flammable gas

I'll try to make the gearing between the compressor and turbine adjustable on the fly, so I can adjust it according to the heat available by just turning a knob.
If it works on atmospheric pressure I'll turn it into a closed loop system that I can pressurize.

Wow, was it really december since I last visited here? Time really flies. Had some other things to take care of, so I couldn't work on this. But the thinking never stopped.

I recently got back into it because a friend gave me a nudge I wasn't expecting. In stead of Stirling engine I'm now looking at a brayton cycle with Tesla turbines.
It fills the needs for less moving parts, combining functions and ease of construction.

I would only have one shaft, with a turbine, a pump and a generator. The moving discs are basically the flywheel and work is mostly done on the outer edge of that. The generator, or load, is on a much smaller arm compared to the shaft.
The pump would pump air, and maybe added water through a venturi, into the Tesla valve heat exchanger. The valves hopefully allow most pressure to be built up on the downstream side to power the turbine. The water/steam will condensate and be drained for pickup later. This way the pump will pump dry air into the heat exchanger again.

As usual, I don't know if I'm explaining this in a way others can understand. Jeremiah on YouTube has some good info.

I get the premise. I and many others have been hoping someone would make a heated tesla valve. Seems to have lots of potential.

I think so too. I'll first try to get my hands on a Tesla valve to run some tests. I can't readily find a metal one, so I might have to get one made.