solar powered stirling engine project

[illuminatty]

I'm currently working on a project for a Stirling engine for school,I'm a third year engineering student with access to machinery. I've been looking at creating a parabolic reflector out of aluminum or of Fresnel lenses, but I'm not really sure which. I'm also considering using a glass cylinder with a graphite piston, but I've been reading online that you should incorporate acrylic and a black displacer somehow but I'm not really sure how or why. I'm not sure if the acrylic replaces the glass cylinder or if you add an acrylic layer to that. Sorry if I seem a little lost, there's so much information to take in! Thank you :)

[Fly_25R]

I am also working on my first engine.

how large is this engine going to be? less than 1" piston?
gamma engine?
i would use the parabolic mirror
i would stay away from acrylic because it could possibly melt
the black displacer would be helpful assuming you have a clear cylinder so is could absorb light and convert is to heat

for a small engine use a large borosilicate glass test tube
boro glass has a low coefficient of expansion so it won't crack easily

[illuminatty]

The maximum size dimensions for the engine is 14”x10”x10” (inches), and the budget can't exceed $80 usd (which is another point of trouble). My team and I have been prioritizing making an alpha type, just because it seemed easier to incorporate just a piston + cylinder versus having to think about the damper too. Honestly not sure how to go about that either. Thank you for the suggestions!

[Tom Booth]

The maximum size dimensions for the engine is 14”x10”x10” (inches), and the budget can't exceed $80 usd (which is another point of trouble).

Do those dimensions include the parabolic reflector or fresnel lense, or is that the engine alone?