View Full Version : If I run a table fan on any planet.....

2007-Feb-10, 12:50 PM
If I run a table fan on the earth with a constant energy provider, it will be rotate as far as the last energy input, but the same If I do in space or on any other planet by providing the same energy input will that fan continues the normal functions, is that fan may suffer from the electro magnetic waves in the space and how? What impact falls on the fan (on its rotations) in the vaccum!

Nowhere Man
2007-Feb-10, 01:40 PM
An electric fan is no more than a crude, tough electric motor with fan blades attached. Its EM environment should make no difference to its operation.

If it's in a vacuum, then naturally there's no air (gas) for it to move, so it just spins. It might spin a bit faster because there's no drag.


2007-Feb-10, 02:15 PM
The other issue of running rotating equipment in space is the vacuum effect on lubrication. Rotating shafts are often machined in close tolerance to their guiding holes, so lubrication is necessary to avoid excessive heat buildup from friction. On Earth and at ~ sea level, there's ~ 1 atmosphere of aie pressure. An oil has a vapor pressure which increases with temperature, and will slowly volatolize, escaping into the air. This is exacerbated in space as there is no atmospheric pressure to limit it to a slow diffusion. For this reason, early vacuum pumps and systems use high molecular weight vacuum greases which volatilize much more slowly....and would give your fan greater longevity spinning in space.
You also didn't mention if the fan were attached to a more massive object, like the shuttle. If it were mounted externally (after achieving orbit).so that it's propeller axis was aligned with the longitudinal axis of the shuttle, and then turned on (notice the little plug mounted on the shuttle:D )...then to conserve angular momentum, when the prop rotates one way, the shuttle will go the other. Due to precession effects, if the fan were to oscilllate "left" and "right", the shuttle would nose "up" and"down". High speed gyros designed to operate in vacuum, with magnetic levitation, point the Hubble Space Telescope. Pete