Search found 3120 matches

by Tom Booth
Wed Feb 07, 2024 4:16 pm
Forum: Stirling and "Hot Air" Engine Forum
Topic: Atmospheric pressure ?
Replies: 33
Views: 1565

Re: Atmospheric pressure ?

In a way, thinking about it a bit, It takes a vacuum pump a considerable expenditure of energy to completely evacuate a vacuum chamber. Water, or a very little water vapor inside a 55 gallon drum can "create" a vacuum as a result of condensation. That may be apples to oranges. I suppose, b...
by Tom Booth
Wed Feb 07, 2024 12:02 pm
Forum: Stirling and "Hot Air" Engine Forum
Topic: Atmospheric pressure ?
Replies: 33
Views: 1565

Re: Atmospheric pressure ?

Tom, What I see a few posts up, is a quote about a process seen in Botany , where sap gets lifted up trees beyond what 'positive pressure' can explain. I can't pretend to provide a full explanation of how capillary action works, but I do know that it has at least something to do with "surface ...
by Tom Booth
Wed Feb 07, 2024 11:06 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: Atmospheric pressure ?
Replies: 33
Views: 1565

Re: Atmospheric pressure ?

...I've had a global shutter high-speed video camera for a lot of years, ... Add that asset to my offer of a vacuum chamber experiment. ... That would be great. Something like the hot air (or steam or both) in a jar with a balloon tightly sealed over the mouth of the jar with a rubber band, put int...
by Tom Booth
Wed Feb 07, 2024 10:44 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: Atmospheric pressure ?
Replies: 33
Views: 1565

Re: Atmospheric pressure ?

If the "working fluid" is not only doing work while expanding and pushing the piston, but also doing work while contracting and pulling the piston, like a stretched rubber band might pull an object as it "relaxes", that might result in an additional temperature drop of the workin...
by Tom Booth
Wed Feb 07, 2024 10:31 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: Atmospheric pressure ?
Replies: 33
Views: 1565

Re: Atmospheric pressure ?

I'm thinking of a piston returning to TDC "by atmospheric pressure" without any apparent means for heat removal. I think these are two completely and totally unrelated matters, which may be part of the confusion. The power piston in a gamma engine has zero role in heat transfer/removal. I...
by Tom Booth
Wed Feb 07, 2024 4:33 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: Atmospheric pressure ?
Replies: 33
Views: 1565

Re: Atmospheric pressure ?

I'm thinking of a piston returning to TDC "by atmospheric pressure" without any apparent means for heat removal. I think these are two completely and totally unrelated matters, which may be part of the confusion. The power piston in a gamma engine has zero role in heat transfer/removal. I...
by Tom Booth
Wed Feb 07, 2024 4:10 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: Atmospheric pressure ?
Replies: 33
Views: 1565

Re: Atmospheric pressure ?

Or... Since we really want to know about hot air engines, rather than steam... Just warm the jar, put on the lid with the balloon, or tie the balloon on with the rubber band. Put that into the vacuum chamber. If gas NEVER "sucks" by molecular adhesion or whatever, the balloon should never ...
by Tom Booth
Wed Feb 07, 2024 3:52 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: Atmospheric pressure ?
Replies: 33
Views: 1565

Re: Atmospheric pressure ?

Maybe a simple "pressure gauge" could be just a rubber diaphragm, like a piece cut from a heavy latex glove. Instead of a pressure gauge just cover the jar with a section of rubber gloves or perhaps just a balloon held on with a rubber band? Or held on by a canning jar lid rim, without the...
by Tom Booth
Wed Feb 07, 2024 3:28 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: Atmospheric pressure ?
Replies: 33
Views: 1565

Re: Atmospheric pressure ?

Maybe instead of an egg. That would probably be too difficult to keep the steam in the bottle from being sucked out by the vacuum pump. Instead put a screw top on the bottle, maybe use a canning jar. On the lid of the canning jar have a simple pressure gauge. Now boil some water in the bottle fillin...
by Tom Booth
Wed Feb 07, 2024 1:54 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: Atmospheric pressure ?
Replies: 33
Views: 1565

Re: Atmospheric pressure ?

Or... Maybe the ordinary old egg in a bottle trick. Put some water in a milk bottle. Boil and peel an egg. Put the bottle into a pan of boiling water until the water inside the bottle starts to boil filling the bottle with steam. Put the hard boiled egg on top and tansfer the pan and bottle into the...
by Tom Booth
Wed Feb 07, 2024 12:58 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: Atmospheric pressure ?
Replies: 33
Views: 1565

Re: Atmospheric pressure ?

Or, what if we were to do the steam condensing in a can experiment, but before the can can cool and collapse, put it inside a vacuum chamber. Would the "attractive" force of the condensing steam collapse the can without the external atmospheric pressure? No. No collapse if done under vacu...
by Tom Booth
Tue Feb 06, 2024 11:29 pm
Forum: Stirling and "Hot Air" Engine Forum
Topic: Atmospheric pressure ?
Replies: 33
Views: 1565

Re: Atmospheric pressure ?

...everything he has mentioned so far is explained by conventional physics,... I'm not necessarily saying it isn't. However, "conventional physics" covers a lot of Territory and is not always consistent. Probably 99% of any issue I have with physics. (I'm assuming you mean me and not the ...
by Tom Booth
Tue Feb 06, 2024 8:46 pm
Forum: Stirling and "Hot Air" Engine Forum
Topic: Stirling engine fan for top of woodstove
Replies: 18
Views: 1711

Re: Stirling engine fan for top of woodstove

My sterling engine fan came oin today. Not impressed with it....the shaft that the propellor mounts to is either bent or the small bearing it rides on, is sloppy....Dont waste your money on this unit Sorry to hear that. Unfortunately, typical of what's generally available on the market. Basically n...
by Tom Booth
Tue Feb 06, 2024 6:51 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: Atmospheric pressure ?
Replies: 33
Views: 1565

Re: Atmospheric pressure ?

Similarly, a 55 gallon drum suddenly collapsed when filled with steam, then cooled. How does the steam condense in a vacuum that isn't a vacuum until the steam condenses but if water were to condense it would boil and produce cold steam. The parameters are changing as the event transpires. It start...
by Tom Booth
Tue Feb 06, 2024 3:13 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: Gigantic LTD
Replies: 2
Views: 300

Re: Gigantic LTD

... So why the focus on the mass of the displacer? Properly counterbalanced it should not consume any more energy to move it, be it 1g or 1kg, ... Inertia? In most cases, in a reciprocating engine. The moving parts, like the piston and displacer are initially at rest, then have to move to a differe...