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Re: Isolated cold hole
Posted: Mon Nov 18, 2024 10:21 am
by Tom Booth
How I conceptualize this is you are not just pushing the piston you are pushing the gas being compressed in front of the piston.
So to get maximum force you want to start compressing the gas (pushing back by introducing heat) when the piston is traveling at maximum velocity.
The maximum return velocity of the piston (returning from BDC to TDC) is always at the midway point of the stroke between BDC and TDC.
Maximum acceleration of the piston is at the half way mark or exactly 90°
By introducing heat at that point you get the most "spring" compression which translates into the most force for the power stroke.
Edit: Fool, this has nothing to do with gear ratios.
Re: Isolated cold hole
Posted: Mon Nov 18, 2024 10:32 am
by Fool
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I know, but there are several points being made here and in YouTube.
If you are making the point that Stirling engines can be tuned for specific rpms and power levels, great. Your descriptions of harmonic motion, spring/mass/damper, and resonance, systems and how they apply to Stirling engines, is comical at best. Learn some integral calculus. Learn some kinematics.
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Re: Isolated cold hole
Posted: Mon Nov 18, 2024 12:31 pm
by Tom Booth
Fool wrote: ↑Mon Nov 18, 2024 10:32 am
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I know, but there are several points being made here and in YouTube.
If you are making the point that Stirling engines can be tuned for specific rpms and power levels, great. Your descriptions of harmonic motion, spring/mass/damper, and resonance, systems and how they apply to Stirling engines, is comical at best. Learn some integral calculus. Learn some kinematics.
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First of all, no, I'm not "making the point that Stirling engines can be tuned for specific rpms and power levels"
Second of all, this is not at all difficult to understand or demonstrate, with or without mathematics.
Anyone can play around with the timing on a Stirling engine and find the displacer advance setting that produces the greatest torque and power.
BTW that type engine out of the box using graphite dry lubricant is likely to be disappointing. I couldn't get it to light the LED when heated with a propane torch.
But after some modifications and using a non-flammable liquid lubricant the compression was too high and it wouldn't run at all, until I reset the timing to exactly 90°
Re: Isolated cold hole
Posted: Mon Nov 18, 2024 12:46 pm
by Tom Booth
Fool wrote: ↑Mon Nov 18, 2024 10:32 am
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...
Your descriptions of harmonic motion, spring/mass/damper, and resonance, systems and how they apply to Stirling engines, is comical at best. ...
Oh, really? How so? What's so comical about it.
Re: Isolated cold hole
Posted: Mon Nov 18, 2024 2:16 pm
by VincentG
The only thing that creates power is more pressure in the cylinder on the down stroke and more pressure in the buffer space on the up stroke. Standard 90 degree phasing is just a compromise that allows the engine to run. It is elegant in its simplicity but in no way optimal.
Why would you want to start increasing cylinder pressure and introduce heat 90 degrees before tdc?
Not only does that completely ruin any chance of isothermal compression but it makes compression even less efficient than 100% adiabatic compression would be.
You have done the same experiment I have that proves internal pressure is directly connected to the position of the displacer in the chamber.
Re: Isolated cold hole
Posted: Mon Nov 18, 2024 3:31 pm
by Tom Booth
VincentG wrote: ↑Mon Nov 18, 2024 2:16 pm
The only thing that creates power is more pressure in the cylinder on the down stroke and more pressure in the buffer space on the up stroke. Standard 90 degree phasing is just a compromise that allows the engine to run. It is elegant in its simplicity but in no way optimal.
Why would you want to start increasing cylinder pressure and introduce heat 90 degrees before tdc?
Not only does that completely ruin any chance of isothermal compression but it makes compression even less efficient than 100% adiabatic compression would be.
You have done the same experiment I have that proves internal pressure is directly connected to the position of the displacer in the chamber.
You are compressing a spring.
The energy is not lost just temporarily stored in the "air spring" then returned with the power stroke.
What you are storing is the energy derived from atmospheric pressure on the return stroke and adding that together with the energy from the heat input.
And .maybe an extra kick from mashing all those gas molecules together and heating them so the electron clouds overlap and repel.
Adding heat during compression increases the pressure and heat generated causing more electrons to jump to higher orbits (more rapid expansion).
These factors more than compensate for any supposed "back work".
That's my working hypothesis anywho.
Re: Isolated cold hole
Posted: Mon Nov 18, 2024 11:13 pm
by Tom Booth
Fool wrote: ↑Mon Nov 18, 2024 10:16 am
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Tom, I get little to nothing out of your videos. It appears as if other people have the same issues, as you have very few followers. I read the comments on the first of the last two you linked.
@sierraecho884 and you had one of your usual spats with people....
...As @sierraecho884, basically said, ....
....As far as getting more followers, improve the professionalism of your videos. People get motion sick from watching a lot of camera waving, waving things in front of the camera, zooming in and out, and worse combined with poor focus. Use a tripod. Discus with someone what the real reason is for the phenomenon you are presenting. Don't argue with your commenters, a real turn off. Let them argue with themselves, you will build supporters. Ask them questions. Example: Why does it power more LEDs after the gear change?
People lose interest if they don't know what is going on, talk them through the presentation. Like Alpha Phoenix, or Veritasium. Or others.
Your presentation needs sharpening....
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When you start your own channel you can run it however you like.
@sierraecho, like you, is a useless, meddlesome, know-it-all Troll who should be blocked and deleted.
Re: Isolated cold hole
Posted: Tue Nov 19, 2024 10:02 am
by Fool
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You have no clue, whom is trying to help. If they disagree they become your target. I don't think you will ever learn how to get help from everybody. It is possible, but it requires tact.
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Re: Isolated cold hole
Posted: Tue Nov 19, 2024 12:27 pm
by Tom Booth
Fool wrote: ↑Tue Nov 19, 2024 10:02 am
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You have no clue, whom is trying to help. If they disagree they become your target. I don't think you will ever learn how to get help from everybody. It is possible, but it requires tact.
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Derailing a conversation, character assassination, interfering with, spamming research projects, trolling, sabotaging, DOXing, spreading FUD, etc. is not "help"
I've been the target of your kind of "help" enough to know the difference.
Re: Isolated cold hole
Posted: Wed Nov 20, 2024 7:28 am
by Fool
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Yep you sure do all that.
Tommy wrote:These factors more than compensate for any supposed "back work".
You fail to include those atmosphere spring compressions during the forward stroke, so the forward work generated is reduced by the same amount as the original back work. Duh!
You won't do good science by choosing ignorance.
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Re: Isolated cold hole
Posted: Wed Nov 20, 2024 7:18 pm
by Tom Booth
Fool wrote: ↑Wed Nov 20, 2024 7:28 am
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Yep you sure do all that.
Tommy wrote:These factors more than compensate for any supposed "back work".
You fail to include those atmosphere spring compressions during the forward stroke, so the forward work generated is reduced by the same amount as the original back work. Duh!
You won't do good science by choosing ignorance.
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You don't even make any sense, and obviously don't even know what your talking about.
You should choose to learn how to construct a sentence.
Re: Isolated cold hole
Posted: Thu Nov 21, 2024 12:25 am
by Fool
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You are cherry picking and ignorant.
When you can put together a PV diagram of this mythical engine cycle that has zero back work, come back and supply it.
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