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I used to own a big old teak built Royal Navy launch, fitted with a Glennifer 4 cyl 13 litre diesel engine. It started on compressed air. While the engine was running, you could switch a valve on No. 3 cyl to recompress air into the tank. If you failed to start the engine with the air next time, you...

Let's start saying 1000 Joules just to give this some scale. I have not yet seen any data showing where or how the extra 1000 Joules are used by the gas to lift 1000 Newtons, as compared to just expanding against the atmosphere. Are we going to scale up the volume of air to 100,000cc too? This matt...

Great. Have a good evening.

If moving from the copper bar to the 5lb steel block made no noticeable difference to the compression of the gas, you can probably understand why I thought the compression caused by the 102g piston wasn't worth calculating out. But I'm interested to know what you think about my response to your 'des...

Sorry to hear that. As an engineer, you likely deal with scaling all the time. This is just a peanut size example. I was able to set 5 pounds of steel into oscillation with just a 40 degree Fahrenheit temperature difference and my 15cc epoxy displacer chamber. The only limit to this weight, even at...

I'm an engineer, not a forensic nitpicker. I do practical calcs good enough to get the job done, and don't bother about negligible additional forces. That's because nothing ever lives up to its theoretical promise anyway. :laugh: If you want to know how many millimetres or extra pascals the gas comp...

We already did the math in previous posts. The joule symbol: J, is the unit of energy in the International System of Units (SI). It is equal to the amount of work done when a force of one newton displaces a mass through a distance of one metre in the direction of that force. https://en.wikipedia.org...

The extra 1J gives the gas the pressure it needs to lift the weight of the piston through 1m.
The extra 1J is stored in the piston at it's new altitude as gravitational potential energy.

At 150 bar of pressure I wouldn't want to be anywhere near MTI's engine when Tom disconnected the coolant flow to show the design engineers how much better it'd work without it. :laugh: Highly pressurised Stirling engine efficiency isn't much different than nuclear reactors or coal fired plant, thou...

Yes, but I think first half of the compression piston stroke would be a better description. Thanks, that is what I meant. The output per cycle was likely so low that it required a team of horses to spin up the flywheel prior starting. It's almost an open cycle Stirling where the "hot side"...

Matt, yes, and the Chambadal-Novikov efficiency I started this thread with comes out at η = 1 – √(418.5/800) = 27.7% It should be noted that calc is using the Th and Tc internal gas temperatures not the external heater and cooler temperatures. A pretty accurate result from an elegantly simple equati...

https://ntrs.nasa.gov/api/citations/20080025987/downloads/20080025987.pdf The Component Test Power Convertor The CTPC is a 12.5-kWe free-piston Stirling convertor designed, built, and tested in the late 1980s and early 1990s by Mechanical Technology Inc. (MTI) (ref. 5). The convertor took heat from ...

The only other viable route from wood-fire to battery charging seems to be Thermo-Electric Generators. TEGs. The modules are coming down in price - around $15-$20 for a 6.5W unit on AliExpress. 10 of those plus some watercooling kit and a heavy duty heatsink to keep the hot side thermally and mecha...

When is air being vented to atmophere by the Wilcox engine? The first half of the compression phase?

Energy required to expand the gas to 200cc AND lift a 1N weight by 1m = 36.5J + 1J = 37.5J