Hot air engine heated by magnifying glass instead of flame?

[Cavalier68]

I have a hot air Stirling engine model with a flame that heats a glass cylinder. I tried focusing sunlight on the glass cylinder instead of a candle flame and the engine does not work that way. I think it would be interesting to get it working using the focused sunlight. Any helpful suggestions would be appreciated. Thanks.

[Bumpkin]

Hi Cavalier68 Remember that solar heat needs a good absorber before it can then conduct to air. Some solar Stirling engines purposely have windows into an internal heater matrix. If your engine is only glass at the heated portion, maybe you could just blacken it. It would still be difficult to direct heat all around the glass tube like a flame does. Bumpkin

[Tom Booth]

It can work, but it seems a very big magnifying lense is needed in order to produce enough heat for that type of "high heat" Stirling:

https://youtu.be/CDCTANU8Tfk

On the other hand an LTD Stirling can operate with just direct sunlight without any magnification:

https://youtu.be/Q1SnG_1VMTM

[Rob1962]

Very interesting.Thank you for sharing.

[Rob1962]

Very interesting. Thank you for sharing.

[Nobody]

Try directing the light to the top of the piston?

[airpower]

Fresnel lenses can melt glass, steel and rocks, no candle flame will produce that kind of temperature.
https://youtu.be/xyCH2T5PWUc