Stirling engine question.

[Peter.]

Looking at the 'miser' type sterling engines, I was wondering:

Do they work best with a very thin top and bottom heat-transfer plate in the displacement cylinder or do they prefer a thicker plate in order to store heat energy?

 

[Peter.]

How the heck did I post this in Plans?

Sorry - can a mod please move it to Q&A?

 

[b.lindsey]

A thicker plate would store more heat energy and the top (cold) plate would stay cooler longer but it would also take more time for the bottom plate to heat up I think, depending on what you were using for a heat source. Ifi you are considering a "miser" or similar engine, I would recommend staying with the stated dimensions for plate thickness....IIRC 1/8" for the full size miser and 1/16" for the half scale version.

Bill

 

[joeby]

Keeping in mind that what you are trying to accomplish is heating and cooling of the air inside the engine and not the plates themselves; I don't think a thicker plate would be an advantage. It seems to me that it would slow the heat transfer.

Something to experiment with maybe.

Kevin

 

[Stan]

If you are building from a proven plan, it is best to follow the bill of materials. If you are building to your own design, be prepared for a lot of empirical experimentation.

In many Stirlings, the hot end in particular is critical. The rate of heat transfer of the material used makes the difference between a non runner and a good runner. The wrong material may work but require a lot more heat to run.

 

[Peter.]

Not planning to build from plans Stan. I prefer to build from my head.

I have some .024" ally sheet which I was planning to use for the top & bottom of the displacement cylinder, thinking that the thinner material would give a more direct 'connection' to the differential ambient temperatures outside. My idea is that using thicker material might give a short-term advantage but only until they reached a'soaked' state, at which time the machine would still only react (albeit slowly) to the differential temperatures outside.

I don't know how far off-base I am with my reasoning but that's how I see it.

 

[Mainer]

Not an answer to your question (I don't know, anyway) but here's another idea: put fins on the top plate, for better heat dissipation. (I don't know if that would make any difference, either....)

 

[deverett]

Another query on LTD displacer cylinders: Would there be any advantage to making the bottom plate out of copper instead of the usual aluminium?

Dave
The Emerald Isle