Getting energy from kinetic motion of air particles

AI Thread Summary
The proposed equipment aims to harness the kinetic motion of air particles to rotate a mill, similar to Crooke's radiometer but utilizing 3-dimensional vanes shaped like pyramids or cones. The design features one side of the vane with a larger surface area to create a net force from air particle collisions, potentially leading to rotation. The discussion raises questions about whether this setup would generate any rotation, considering factors like the direction of molecular impacts and the effects of surface area. It is noted that the device may perform better under higher air pressure rather than in a partial vacuum. Overall, the concept suggests that varying surface areas on the vanes could indeed facilitate rotation.
ZawL
Messages
3
Reaction score
0
I am proposing a piece of equipment a bit similar to Crooke's radiometer with the aim of using kinetic motion of air particles to rotate the mill, without need for an external source of EM radiation.

Instead of flat vanes as in Crooke's radiometer, I propose 3-dimensional vanes in the shape of a pyramid, cone or frustrum. The idea is for one side of the vane to have a larger surface area than the other side so that more of the air particles will hit the larger side and create a net force that causes the mill to rotate.

I would like to know whether this setup would theoretically produce rotation of the mill, however tiny. And if not, then why not? I realize there is some complication with the direction at which molecules hit the different surfaces which could cancel out any factor due to larger surface area. Does this always produce a net force of zero regardless of what shapes the two surfaces are? My setup obviously does not work as well under a partial vacuum as in Crooke's radiometer and could actually work better under higher air pressure.
 
Physics news on Phys.org
A picture would really help. But yes, if it presents a different surface area on one side than the other, it will rotate.

The thing below (used to scare away birds) has movable vanes, but it depends on the same principle.

 
The rope is tied into the person (the load of 200 pounds) and the rope goes up from the person to a fixed pulley and back down to his hands. He hauls the rope to suspend himself in the air. What is the mechanical advantage of the system? The person will indeed only have to lift half of his body weight (roughly 100 pounds) because he now lessened the load by that same amount. This APPEARS to be a 2:1 because he can hold himself with half the force, but my question is: is that mechanical...
Some physics textbook writer told me that Newton's first law applies only on bodies that feel no interactions at all. He said that if a body is on rest or moves in constant velocity, there is no external force acting on it. But I have heard another form of the law that says the net force acting on a body must be zero. This means there is interactions involved after all. So which one is correct?
Thread 'Beam on an inclined plane'
Hello! I have a question regarding a beam on an inclined plane. I was considering a beam resting on two supports attached to an inclined plane. I was almost sure that the lower support must be more loaded. My imagination about this problem is shown in the picture below. Here is how I wrote the condition of equilibrium forces: $$ \begin{cases} F_{g\parallel}=F_{t1}+F_{t2}, \\ F_{g\perp}=F_{r1}+F_{r2} \end{cases}. $$ On the other hand...
Back
Top