Calculation of a solar parabola: focus, curvature ...

[Christophe]

You can also read again the beginning of this subject, you would have found this link: https://www.econologie.com/telechargeme ... satellite/

I advise you to start with a star mesh to start ...

[ABC2019]

Uh is the shape parabolic? I have a little doubt because any bowl is not parabolic ...

You can easily check if the curvature is parabolic with the technique I indicated in my previous message.

on the other hand as explained above if we are not looking for a pretty well punctual focal point, we do not care a bit, any more or less spherical shape will already cause a concentration of the rays at a distance equal to half the radius of curvature (radius of the sphere as close as possible to the surface)

[Christophe]

Is that so ? Your lack of rigor on this one calls me knowing you ...

A sphere will waste most of the energy: theoretically only the rays arriving at the center (bottom of the sphere) will be reflected on the focal length = center of the sphere! Bad luck (no pun intended) it is at this level that we put the "collector" ...

So no a sphere does not allow to make a solar cooker!

[ABC2019]

Is that so ? Your lack of rigor on this one calls me knowing you ...

A sphere will waste most of the energy: theoretically only the rays arriving at the center (bottom of the sphere) will be reflected on the focal length = center of the sphere! Bad luck (no pun intended) it is at this level that we put the "collector" ...

So no a sphere does not allow to make a solar cooker!

if the focal spot is smaller than the size of your container, it does not matter: on the contrary it distributes the heat more evenly instead of concentrating it at one point, in the same way as a burner has several flames and not one. Finally, I imagine because I have never used such a device .

[Arthur b]

It's ok I got it !
After doing the test I got a result close to the curve of my dish but there is a few cm of offset, do I have to correct everything or else it can still work.

[jmfrigerio]

To get a parabolic shape, you just have to flame (buckling, not burning, eh) the materials!

Naturally the flat profiles of homogeneous common materials take on a parabolic shape (as long as they do not enter the plastic strain at the most constrained pointss)! And the more you burn, the closer the home will be!

To obtain a linear dish, it suffices to compress any rectangle of a fairly thin and flexible material ....
To obtain a parabola, simply assemble X flamed slats in the same way ...

Hello,

I come back to this buckling, which intrigues me a lot, I admit.

Do I understand correctly if I say that by joining the 2 ends of say a concrete iron rod (diam 6mm) 3m long with a 2m cable I get a parabola?

Thank you for your lights

[Remundo]

approximately, yes.

A single curvature parabola (cylindrical-parabolic mirror).

[GuyGadeboisTheBack]

What knowledge!

[Ahmed]

In this regard, the least we can do is to be dazzling!

[Christophe]

approximately, yes.

A single curvature parabola (cylindrical-parabolic mirror).

And a parabola made it an assembly at 60° of 6 (at least) of these elements by their center...