Search found 14 matches

by goat
Tue Apr 03, 2012 3:23 pm
Forum: Stirling and "Hot Air" Engine Forum
Topic: Carnot engine
Replies: 16
Views: 14313

Re: Carnot engine

Lucien01,

You can get heat to flow from a cooler body to a hotter body without doing any work? Wow!

I look forward to seeing that in action.
by goat
Tue Apr 03, 2012 3:15 pm
Forum: Stirling and "Hot Air" Engine Forum
Topic: Carnot engine
Replies: 16
Views: 14313

Re: Carnot engine

Hi Serge, The document you linked to says that it shows that an Carnot cycle has maximum efficiency for a range of different power regimes, not just at maximum power. For the engines that the guys on this forum are making, I don't think that's particularly important. The actual cycle taking place in...
by goat
Tue Apr 03, 2012 2:39 pm
Forum: Stirling and "Hot Air" Engine Forum
Topic: Stirling-Inspired Turbine
Replies: 5
Views: 7920

Re: Stirling-Inspired Turbine

Hi Pete,

That's essentially what they do in power stations, so yes, it would work.
by goat
Sat Jun 05, 2010 1:22 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: Stirling Turbine
Replies: 48
Views: 52627

Re: Stirling Turbine

Tom Peat,

Sorry, my post was in response to Tom Booth's original posts, rather than yours. I should have made that a bit clearer. My mistake. :mrgreen:
by goat
Tue Jun 01, 2010 12:02 pm
Forum: Stirling and "Hot Air" Engine Forum
Topic: Stirling Turbine
Replies: 48
Views: 52627

Re: Stirling Turbine

Tom, I'm not sure that you can wring work out of a the air in the way that you originally described. The stage in which you extract work from the air using a turbine, making the air very cold, would also reduce the pressure of the gas to a very low pressure. When you came to exhaust the air back int...
by goat
Tue Jun 01, 2010 11:12 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: Stirling Engine Thermodynamics
Replies: 251
Views: 311307

Re: Stirling Engine Thermodynamics

I'm not at all sure what you mean here by "lagging the cold sink". Over here we sometimes call insulation lagging - sorry I didn't realise you guys didn't use the word that way, too. I should have looked that up, apologies. Anyhow, what I meant was insulating the cold sink. Oh, and 'cold ...
by goat
Tue Jun 01, 2010 11:03 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: Better engine
Replies: 7
Views: 8554

Re: Better engine

I'm not sure that it's true that the heating and cooling phases produce the same power, that's probably worth reading up on. What I am pretty sure of is this: If the working gas is expanding then power is coming out, but you have to put power in to get the gas to compress. The reason I think this is...
by goat
Wed May 19, 2010 2:57 pm
Forum: Stirling and "Hot Air" Engine Forum
Topic: Stirling Turbine
Replies: 48
Views: 52627

Re: Stirling Turbine

Klein bottles are cool, aren't they. A friend showed me one a few years ago and I've always wished I was good enough at glass blowing to make one myself since. I'm not sure one would be needed to set up a continuous Stirling engine, though. Surely you could set a Stirling circuit up in a similar man...
by goat
Wed May 19, 2010 2:33 pm
Forum: Stirling and "Hot Air" Engine Forum
Topic: Stirling Engine Thermodynamics
Replies: 251
Views: 311307

Re: Stirling Engine Thermodynamics

Sorry again, my bad. I should have read your posts a bit more carefully and I'd have seen you knew about that. You said that people say: but they tell you its still 30% of the heat energy making more HP In the case of super or turbocharging that won't be the case. I believe the higher pressure diffe...
by goat
Mon May 17, 2010 1:58 pm
Forum: Stirling and "Hot Air" Engine Forum
Topic: Hot Potato Engine
Replies: 1
Views: 4499

Re: Hot Potato Engine

Hi Tom, You have a load of ingenious ideas, I like it. I'm not sure that you can call your 'hot potato' a regenerator, though. The regenerator in a Stirling engine absorbs heat from the working fluid as it passes from the hot source to the cold sink and gives it back to the working gas when it passe...
by goat
Mon May 17, 2010 11:46 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: Stirling Engine Thermodynamics
Replies: 251
Views: 311307

Re: Stirling Engine Thermodynamics

Longboy,

Many apologies, I've just noticed I called you 'Longpig' in my last two posts. :shock: Please forgive me, I didn't mean to be rude.
by goat
Sun May 16, 2010 3:53 pm
Forum: Stirling and "Hot Air" Engine Forum
Topic: Stirling Engine Thermodynamics
Replies: 251
Views: 311307

Re: Stirling Engine Thermodynamics

Longpig, By the way, there are a couple of main ways that engineers can make an engine put out more power with the same ccs: 1) They increase the incoming pressure by adding rams, a supercharger or a turbocharger (or two). The efficiency of the engine is related to the incoming pressure, so you get ...
by goat
Sun May 16, 2010 3:40 pm
Forum: Stirling and "Hot Air" Engine Forum
Topic: Stirling Engine Thermodynamics
Replies: 251
Views: 311307

Re: Stirling Engine Thermodynamics

Longpig, Good point, it'd be difficult to stop the working gas from escaping unless you could make a properly sealed cylinder. Tom, I've had another read through of your first post & the wikipedia entry on Stirling engines and in the cold light of day here's what I'm thinking. Let me know if I'm...
by goat
Sat May 01, 2010 7:10 pm
Forum: Stirling and "Hot Air" Engine Forum
Topic: Stirling Engine Thermodynamics
Replies: 251
Views: 311307

Re: Stirling Engine Thermodynamics

I was thinking it would be cool to use a light-collector Stirling engine to power a camera in an unmanned high-altitude balloon (like this: http://news.bbc.co.uk/1/hi/england/west_yorkshire/8587749.stm ), but reading this thread I'm worried that it wouldn't work. I've not built any Stirling engines ...