Search found 538 matches
- Mon May 27, 2024 3:45 am
- Forum: Stirling and "Hot Air" Engine Forum
- Topic: Heat is never hot or cold. Internal energy can be hot or cold.
- Replies: 3
- Views: 42
Re: Heat is never hot or cold. Internal energy can be hot or cold.
Q=(T1-T2)A/R Please note that it is a path function going from state T1 to state T2. Kudos Fool - the proper way to 'mix' state and path functions. Thermo notation is almost an art form that ranges from simple statements to complex expressions. The problem is how to 'say' something technically corr...
- Sun May 26, 2024 10:36 pm
- Forum: Stirling and "Hot Air" Engine Forum
- Topic: Seal-less Gamma, bellows, magnetically coupled displacer, rotary
- Replies: 2
- Views: 37
Re: Seal-less Gamma, bellows, magnetically coupled displacer, rotary
The configuration in your second video link is the ancient Gloy (late 1800s patent). Here's another 'spin' which I posted last year: https://www.youtube.com/watch?v=Q3KE0OBRl6E Your first video link is a must see for anyone pondering dwell schemes. Gadz, if Marty can help me fix my flux capacitor, I...
- Sun May 26, 2024 4:29 pm
- Forum: Stirling and "Hot Air" Engine Forum
- Topic: The TRUTH? η = 1 – (Qc / Qh) = 1 – (Tc / Th)
- Replies: 679
- Views: 32339
Re: The TRUTH? η = 1 – (Qc / Qh) = 1 – (Tc / Th)
Understanding all this math stuff is totally unnecessary, but understanding compression cycle theory is paramount to any engine design. The basic takeaway is that an engine runs on a pressure differential and there's various ways to achieve this. Most early engines had no or minimal compression and ...
- Sun May 26, 2024 3:40 pm
- Forum: Stirling and "Hot Air" Engine Forum
- Topic: The TRUTH? η = 1 – (Qc / Qh) = 1 – (Tc / Th)
- Replies: 679
- Views: 32339
Re: The TRUTH? η = 1 – (Qc / Qh) = 1 – (Tc / Th)
In fact I'll do it again. Qh heat added from Tc to get to Th. Not "Q" when Stirling, since this is regen heat within system (vs to or from system). Q always denotes heat between system and surroundings. Uh total energy contained in the gas at Th Uc total energy contained in the gas at Tc ...
- Sat May 25, 2024 2:46 pm
- Forum: Stirling and "Hot Air" Engine Forum
- Topic: The TRUTH? η = 1 – (Qc / Qh) = 1 – (Tc / Th)
- Replies: 679
- Views: 32339
Re: The TRUTH? η = 1 – (Qc / Qh) = 1 – (Tc / Th)
Hey Fool, read this expression out loud and get back to us... Ha ha. Good one. Q=M•Cv•T=U Que equals You with Mee See Vee Tea in the middle. LOL Equating a Q with internal energy in an attempt to explain, as you pointed out "usually" means something else, that variables are just that, var...
- Fri May 24, 2024 1:16 pm
- Forum: Stirling and "Hot Air" Engine Forum
- Topic: The TRUTH? η = 1 – (Qc / Qh) = 1 – (Tc / Th)
- Replies: 679
- Views: 32339
Re: The TRUTH? η = 1 – (Qc / Qh) = 1 – (Tc / Th)
Not sure what you mean. Either energy is transfered into (or out of) the gas or it isn't. Any isothermal process has no net gain or loss of internal energy, only an energy transfer 'thru' gas. So, your "Adding heat increases internal energy, work decreases internal energy." is not always ...
- Fri May 24, 2024 1:12 pm
- Forum: Stirling and "Hot Air" Engine Forum
- Topic: The TRUTH? η = 1 – (Qc / Qh) = 1 – (Tc / Th)
- Replies: 679
- Views: 32339
Re: The TRUTH? η = 1 – (Qc / Qh) = 1 – (Tc / Th)
Temperature equates to internal energy through the following equation: Q=M•Cv•T=U Hey Fool, read this expression out loud and get back to us... Q notation requires extreme care and is usually restricted to a finite value in a relatively 'narrow' expression. I have no problem with common heat usage,...
- Fri May 24, 2024 12:38 pm
- Forum: Stirling and "Hot Air" Engine Forum
- Topic: The TRUTH? η = 1 – (Qc / Qh) = 1 – (Tc / Th)
- Replies: 679
- Views: 32339
Re: The TRUTH? η = 1 – (Qc / Qh) = 1 – (Tc / Th)
Adding heat increases internal energy, work decreases internal energy. In reality for transfers to or from a gas, work or heat are just different words to describe a transfer of kinetic energy in or out of the gas. Actually identical on a molecular or atomic level. Fool likes to imagine some signif...
- Fri May 24, 2024 12:26 pm
- Forum: Stirling and "Hot Air" Engine Forum
- Topic: The TRUTH? η = 1 – (Qc / Qh) = 1 – (Tc / Th)
- Replies: 679
- Views: 32339
Re: The TRUTH? η = 1 – (Qc / Qh) = 1 – (Tc / Th)
Work is a function of pressure x volume. always Pressure is a function of heat applied to a gas. sometimes But that does not mean that heat converts to work. no direct conversion Work is just a consequence of heat. sometimes, but 'consequence' denotes there are constraints and limits Heat creates p...
- Fri May 24, 2024 12:01 pm
- Forum: Stirling and "Hot Air" Engine Forum
- Topic: The TRUTH? η = 1 – (Qc / Qh) = 1 – (Tc / Th)
- Replies: 679
- Views: 32339
Re: The TRUTH? η = 1 – (Qc / Qh) = 1 – (Tc / Th)
"The idea that heat wants to combine with cold, seeks out or finds itself compelled to flow to cold is just Caloric/Carnot theory mythology." Energy has nowhere to go but away from itself. Away from itself is the cold, or cooler. Energy will only stay separated if there are forces keeping...
- Fri May 24, 2024 11:46 am
- Forum: Stirling and "Hot Air" Engine Forum
- Topic: The TRUTH? η = 1 – (Qc / Qh) = 1 – (Tc / Th)
- Replies: 679
- Views: 32339
Re: The TRUTH? η = 1 – (Qc / Qh) = 1 – (Tc / Th)
All three rockets will heat the room equally. Mysteriously then, if the rockets are each placed within their respective piston and cylinder, and the same load differences are applied, the piston engine performing the work of lifting the weight 5ft off the ground will heat the room less? I won't kee...
- Tue May 21, 2024 2:06 am
- Forum: Stirling and "Hot Air" Engine Forum
- Topic: Stirling essex - beta or gamma ?
- Replies: 35
- Views: 7749
Re: Stirling essex - beta or gamma ?
It seems two horsepower was claimed. Maybe they were Shetland ponies? So when does air get drawn back in? Surely not during expansion, when there will be positive pressure?? Yep, near the end of the expansion stroke (see 1/2 dz lines under fig. 11). Hmmm, I doubt the guy who wrote this article saw ...
- Mon May 20, 2024 2:01 am
- Forum: Stirling and "Hot Air" Engine Forum
- Topic: Stirling essex - beta or gamma ?
- Replies: 35
- Views: 7749
Re: Stirling essex - beta or gamma ?
staska - here's the hot/cold gamma comparison within same values where both gamma have same PP volume - enjoy
- Mon May 20, 2024 1:48 am
- Forum: Stirling and "Hot Air" Engine Forum
- Topic: Stirling essex - beta or gamma ?
- Replies: 35
- Views: 7749
Re: Stirling essex - beta or gamma ?
When is air being vented to atmophere by the Wilcox engine? The first half of the compression phase? Yes, but I think first half of the compression piston stroke would be a better description. The output per cycle was likely so low that it required a team of horses to spin up the flywheel prior sta...
- Sun May 19, 2024 11:39 pm
- Forum: Stirling and "Hot Air" Engine Forum
- Topic: Carnot was being too generous
- Replies: 22
- Views: 759
Re: Carnot was being too generous
So, eff was ~25% before alternator. A table like this tells one story, but a PV would tell another. Considering how much time and moola went into this, I doubt we can expect a stand alone CHP anytime soon. I'm all too familiar will this NASA type of stuff, and currently sitting less than 2 miles fro...