Search found 50 matches
- Sat Jun 20, 2020 4:15 pm
- Forum: Stirling and "Hot Air" Engine Forum
- Topic: Tesla's "Ambient Heat Engine" Experiment
- Replies: 175
- Views: 182659
Re: Tesla's "Ambient Heat Engine" Experiment
Given a volume of air, where no air is added or subtracted throughout the cycle. Why would the piston ever bottom out, hitting the orifice, unless the contraction phase were actually stronger than the expansion? If the given volume of air is small enough that the "neutral" point of the pi...
- Sat Jun 20, 2020 3:05 pm
- Forum: Stirling and "Hot Air" Engine Forum
- Topic: large lamina flow build
- Replies: 139
- Views: 159467
Re: large lamina flow build
I can't really picture or imagine what advantage there might be to having the power piston on a cam, or how that would work. Using a cam for the power piston let's you tailor it's motion and dwell time for maximum efficiency. Same reason you want it for the displacer. Some four-stroke engines have ...
- Sat Jun 20, 2020 11:07 am
- Forum: Stirling and "Hot Air" Engine Forum
- Topic: Tesla's "Ambient Heat Engine" Experiment
- Replies: 175
- Views: 182659
Re: Tesla's "Ambient Heat Engine" Experiment
If heat in an expanding gas is kinetic energy that is transfered to the piston and effectively taken out of the system to power an external load, then having made such a transfer of energy, the gas could contract on its own. The piston would return without any help. More accurately, I mean to say, ...
- Sat Jun 20, 2020 9:54 am
- Forum: Stirling and "Hot Air" Engine Forum
- Topic: Is a high power unpressurised stirling engine possible
- Replies: 25
- Views: 9115
Re: Is a high power unpressurised stirling engine possible
Without knowing exactly what the valve cam arrangement is or how it's driven, but just going by your basic description, assuming the cycle continues in the same way, I would be afraid back pressure would prevent the engine running. Wouldn't valve B (pumping air into heating tube) and D (receiving a...
- Fri Jun 19, 2020 8:14 pm
- Forum: Stirling and "Hot Air" Engine Forum
- Topic: Is a high power unpressurised stirling engine possible
- Replies: 25
- Views: 9115
Re: Is a high power unpressurised stirling engine possible
I don't believe heating the air like that would solve the problem. I would think the air would have to be heated inside the cylinder to produce any power. The temperature of the air entering the cylinder is largely irrelevant, it is how much it expands inside the cylinder that determines the power....
- Fri Jun 19, 2020 1:39 pm
- Forum: Stirling and "Hot Air" Engine Forum
- Topic: large lamina flow build
- Replies: 139
- Views: 159467
Re: large lamina flow build
As the power stroke in engines like these is less powerful than traditional combustion engines, you could probably get away with using desmodromic cams instead of a crankshaft for both the piston and displacer so their movement and dwell time allows for maximum heat exchange.
- Thu Jun 18, 2020 6:22 pm
- Forum: Stirling and "Hot Air" Engine Forum
- Topic: Tesla's "Ambient Heat Engine" Experiment
- Replies: 175
- Views: 182659
Re: Tesla's "Ambient Heat Engine" Experiment
The mechanical equivalent of heat (heat and motion or work, are interchangeable) and the conservation of energy, indicate, when heat goes into a heat engine and that engine has produced motion (work), the heat goes out in the form of the external work performed and/or motion produced. If the heat i...
- Sun Jun 14, 2020 8:03 pm
- Forum: Stirling and "Hot Air" Engine Forum
- Topic: Is a high power unpressurised stirling engine possible
- Replies: 25
- Views: 9115
Re: Is a high power unpressurised stirling engine possible
AFIK the only way to get that sudden burst of heat is with internal combustion. Coming at the problem from the other direction and giving the air time to heat up before getting to the cylinder seems the only way to solve it. https://i.imgur.com/eC7rrvr.jpg Granted, the engine has to "breathe&qu...
- Sun Jun 14, 2020 4:43 pm
- Forum: Stirling and "Hot Air" Engine Forum
- Topic: large lamina flow build
- Replies: 139
- Views: 159467
Re: large lamina flow build
Since the end of the tube filled with steel wool is acting as kind of heat reservoir, does that part have to be tube shaped instead of a big sphere or something?
- Sat Jun 13, 2020 9:34 pm
- Forum: Stirling and "Hot Air" Engine Forum
- Topic: Tesla's "Ambient Heat Engine" Experiment
- Replies: 175
- Views: 182659
Re: Tesla's "Ambient Heat Engine" Experiment
You get work out of heat by giving it somewhere to go and making it do something for you in order to get there. You can compare it to a water wheel in that way. It's usually easiest to make a hot spot and use the environment as the cool place the heat tries to flow through. Lower pressure also coun...
- Fri Jun 12, 2020 12:13 pm
- Forum: Stirling and "Hot Air" Engine Forum
- Topic: Tesla's "Ambient Heat Engine" Experiment
- Replies: 175
- Views: 182659
Re: Tesla's "Ambient Heat Engine" Experiment
You get work out of heat by giving it somewhere to go and making it do something for you in order to get there. You can compare it to a water wheel in that way. It's usually easiest to make a hot spot and use the environment as the cool place the heat tries to flow through. Lower pressure also count...
- Fri Jun 12, 2020 9:53 am
- Forum: Stirling and "Hot Air" Engine Forum
- Topic: large lamina flow build
- Replies: 139
- Views: 159467
Re: large lamina flow build
Yeah, like you said earlier, if the stroke of the piston is long enough to let the cylinder pressure drop below atmospheric, outside pressure pushes the piston back in. Effectively a one-stroke engine. Well, one and a half since the up-stroke would be weaker than the down-stroke.
- Thu Jun 11, 2020 10:48 am
- Forum: Stirling and "Hot Air" Engine Forum
- Topic: large lamina flow build
- Replies: 139
- Views: 159467
Re: large lamina flow build
I suspect that in the early version that worked without a flywheel, the piston was acting as a heat sink/radiator.
- Fri Sep 13, 2019 3:07 am
- Forum: Stirling and "Hot Air" Engine Forum
- Topic: Manson cycle turbine
- Replies: 2
- Views: 8280
Re: Manson cycle turbine
Aaaand I managed to screw up the previous image.
- Thu Sep 12, 2019 8:03 am
- Forum: Stirling and "Hot Air" Engine Forum
- Topic: Manson cycle turbine
- Replies: 2
- Views: 8280
Re: Manson cycle turbine
Using vane rotor like so may be better, as it's easier to make. The cam surfaces do need to different sizes though, with the exhaust one producing greater volume than the intake.