forums energies: society, ecology and clean technologies

perhaps a new avenue to explore for making low cost energy: the crook radiometer.





I just saw that in a store in town, the concept is as follows, blades painted on one side in black on the other side in white, on an axis with low friction, all exposed to sunlight in a vacuum atmosphere (partial), it turns;)

SixK

Hello, it uses the solar wind to turn, it is an idea retained by researchers in case a meteor approaches too close to the earth, their idea is to paint it in white so that the sun deviates the trajectory.
but the yield is largely reduced on earth because of the thickness of the atmosphere.
I always wondered if it would work bigger, a big bubble with plates of one m2 ??

the idea is interesting, what is likely to be complicated it is the vacuum of air and the absence of friction which must admit a low developed power. in my opinion, it is also necessary to use very light materials to build the blades. The system can also be filled by a set of mirrors.
I also wonder if a reflection (mental) should not be brought on the colors to be used on both sides of the blade to optimize the yield.

Bonjour.

I would be curious to know on earth what power can be provided by this kind of system. Intuitively, I suppose it must be very small.
I believe that the "solar sail" was considered as a means of space propulsion.
But on earth, the wind "draft" must be able to deliver a power far greater than the solar wind. A wind turbine seems to me easier to make and more profitable.

I did not know this system, thank you for making me discover it.

I have a solar radiometer, it's very old!
it is not the solar wind that turns the fins
in the bulb, in full sun it turns quickly
explanation supplied with the device:
"In the radiometer bulb, there is a partial vacuum produced by
the air which has been rarefied so as to keep a balance between the resistance of the air and the rotary force of solar energy. The black surfaces of the fins absorb more light than the white surfaces which reflect it. contained in the bulb heat up, the higher the pressure
on the black surfaces, the fins then start to rotate
(Bronw's molecular theory) "

Thank you very much for those explanations.

1) Unfortunately we should not hope to recover significant energy with this system if it uses solar winds

You only have to see the very large surface of the solar sails of future spacecraft to be convinced ... knowing that the friction at the top is zero and that the solar winds are probably much more powerful ...

Besides, did you know that NASA was inspired by Japanese folds (remember the name more) for the confinement of these sails?

2) Thank you aladin for the second theory that I understand better ... but then pkoi make a partial vacuum if it is the warming of the molecules that makes things happen?

Finally it is a "wind" solar motor ...

3) Subsidiary question: kk1 knows pkoi it is called a radiometer? It is supposed to measure the light intensity of the sun more than its radiation (but as it is linked ...) ...

The solar wind consists essentially of protons, electrons and helium nuclei with minute traces of ions of heavier elements, such as oxygen or carbon. It escapes continuously and in all directions from the surface of the Sun and bathes the entire solar system.
It will be used on solar sails projects for displacement in space, it is a thrust on any surface, by the mass impact of the various constituents ejected from the sun (journey without return).
It is possible, because it is in a vacuum (no need for optimal CX), conservation of the initial speed and constant acceleration, due to new impacts.
In the radiometer, it's different, since 2 opposing sails are exposed at the same time…
What is more, it is not the white, reflective sail, which is moving away ... but the black sail ...
There is no complete vacuum, but a little air. Which allows molecules to heat up, close to black, and the Brownian movement repels the black veil.
Light intensity of the sun, directly proportional to the heating of molecules, which influence the speed of rotation.
On the site of a young engineer, supported by JP Petit:
http://www.imaginascience.com/boutique/ ... f=111#haut

gegyx wrote:On the site of a young engineer, supported by JP Petit:
http://www.imaginascience.com/boutique/ ... f=111#haut

Not everyone is so lucky ... You have to believe that you have to trade to have Petit's "blessing" ... hihihihi!

Econology wrote:[...]

2) Thank you aladin for the second theory that I understand better ... but then pkoi make a partial vacuum if it is the warming of the molecules that makes things happen? :?:
[...]

Too much air in the bulb = too much friction, wouldn't that make it possible to obtain such a fast rotation speed?