Design process

[wecoppens]

I am looking into designing a new Stirling engine. I have the coffee
cup model and it works well. I am looking at making a large version of
a similar model.

I have put together a model that has a 13 inch displacer. My big
problem is that I cannot get the engine to work.

I am wondering if there are any design verification steps I can go
through to test my design. An example may be as follows: 1) enclose
displacer piston in the displacer cylinder without the displacer rod.
Heat one end of the cylinder and see if the piston rises. 2) add the
displacer rod and seal and heat to see if the cylinder still rises. 3)
Add in power piston and see if it rises. 4) throught in the crank shaft.

If the above process does not work, is there one that does?

If there is no process, are there some design rules of thumbs to go
by?? parameters such a displacer cylinder and piston ratio's #- power
piston and displacer piston ratios #- flywheel weight -vs- power and
displacer pistons.

The displacer piston and cylinder bore / stoke would be great.

Thanks, Bill Coppens

[stan.hornbaker]

I have seen a photo of a Stirling engine made from a charcoal BBQ pan.
The displacer in the pan. Top closed and sealed air tight. Solar heated.
Flywheel, power piston and displacer rod all underneath.

Criteria for a Stirling to run: Sealed air tight except for very small leakage around displacer rod seal. Low friction. Displacer MUST have clearance, not a seal, around its diameter to allow the air to move back and forth.