Stirlingengineforum.com

Spacefog_ wrote: ↑Fri May 17, 2024 5:14 am Anyone know if he's still around, or at least a member of this forum?

Sadly, no. He passed away a couple of years ago.

The best performing FPSE/SE's in general seems to always have another working fluid, and/or expensive, complex. What happened to the KISS-method? KISS is good, but in the case of Stirling engines it's also big and heavy, and wears out its linkage bearings too quickly to send to space. Finely tuned ...

Ok, it may just be me, but I don't have this completely straight. The joules needed to raise 100cc from 300k to 600k at constant volume = ? That's a different and more complex case. Since the pressure will be raised as the gas is heated in a constant volume, the rise in pressure will add to the ris...

. https://seftonmotors.com/products/volo-one-engine That is legitimate. Looks like it could do with a bit of balancing work. :neutral: Waving a voltmeter doesn't tell us anything much either. Running under load? Or not? I'm guessing not, or they'd be proudly showing the illuminated lamps off. https...

Yes. This is what Charles law tells us: "When the pressure on a sample of a dry gas is held constant, the Kelvin temperature and the volume will be in direct proportion." Hence: V1/T1 = V2/T2 The equation shows that, as absolute (Kelvin) temperature increases, the volume of the gas also i...

Fool wrote: ↑Thu May 16, 2024 5:29 pm Stroller,

VincentG's finger will absorb negligible heat. You described a isentropic process. Only one mass, the internal gas.

True. It'll absorb enough for him to feel the increase in temperature of the gas though.

heat is not hot, or internal energy. Temperature is just one variable in internal energy. Work = P•∆V Thermal internal energy U: U=M•Cv•T Heat requires two masses at two different temperatures and a thermal conduction connection. I was taught wrong in school. It took a lot to break that bad thought...

The pressure and temperature won't drop if the right amount of heat/energy is being put into the gas as it expands. ... What determines the "right amount"? Aside from the opinion of "Stroller". "Opinion" :laugh: We can calculate the Work W (in the form of heat energy) ...

Or is 3.65j the energy needed to expand 100cc at 300k to 200cc at 600k? Yes. This is what Charles law tells us: "When the pressure on a sample of a dry gas is held constant, the Kelvin temperature and the volume will be in direct proportion." Hence: V1/T1 = V2/T2 The equation shows that, ...

Charles law states V1/T1 = V2/T2 So if we have a 1cm^2 tube with 100cc of air under the piston, then we need to double its volume to lift our piston by 1m. If we start with 300K air then 100/300 = 200/T2 = 600K 3.65 Joules are needed to raise 100cc of air from 300K to 600K We used 1J raising the 10...

Alternatively, we can calculate the Work W that has to go into the gas to keep it at a constant temperature T as it expands from V1 to V2

W = RTln(V2/V1)

Gas constant R is 0.082 L atm K−1 mol−1

Charles law states V1/T1 = V2/T2 So if we have a 1cm^2 tube with 100cc of air under the piston, then we need to double its volume to lift our piston by 1m. If we start with 300K air then 100/300 = 200/T2 = 600K 3.65 Joules are needed to raise 100cc of air from 300K to 600K We used 1J raising the 102...

Stroller - I think Vincent is suggesting a bang-on demo akin a sloooow isothermal expansion lifting a rock. In this manner, the only 'fuzzy belief' required is that an isothermal expansion has no change in internal energy, whereby all heat input 'must be' converted into work, no ands, ifs, or buts....

I don't follow baseball but I guess you're from across the pond then? For starters, I'd like to see a test conducted that proves actual destruction of heat. Not a reduction of, say, internal energy per cubic centimeter, but actual destruction/ conversion of heat energy. Take a bicycle pump, extend ...

Spacefog_ wrote: ↑Wed May 15, 2024 4:09 pm Does this look legit to you guys? https://www.youtube.com/watch?v=ziZYVbLnSdM

Yeah. 1.4Watt (varying) at full chat looks about right for an enlarged Ky-Ko fan engine design.
It's not going to blow your hat off, but it would trickle charge a motorcycle battery or charge a smartphone.