Thermodynamics of gas in very strong gravitational field.

AI Thread Summary
In a strong gravitational field, gas in a cylinder experiences differential behavior, with the upper half expanding and the lower half compressing, leading to a temperature difference between the two sections. This phenomenon occurs when a strong vertical force is applied, quickly reaching a constant maximum value. The discussion suggests that this temperature gradient is relevant to the principles behind the Ranque-Hilsch vortex tube. The relationship between gravitational forces and gas behavior highlights important thermodynamic principles. Understanding these dynamics can provide insights into various applications in fluid mechanics and thermodynamics.
Spinnor
Gold Member
Messages
2,227
Reaction score
419
Suppose I have a cylinder of gas and at time t=0 I can turn on a strong vertical gravitational force. Let the force change quickly (but a time long compared the mean free path divided by the average gas particle velocity) to reach some constant maximum value F(z,t) = F_max. (This force can be approximately produced by putting the cylinder in a centrifuge that rapidly spins up to some max RPM.)

Can I argue that for very strong force F_max the gas in the upper half of the cylinder will expand and the gas in the lower half of the tube will compress so that there should initially be a temperature difference between the gas in top and the bottom of the cylinder? Is this in effect part of the physics behind the Ranque-Hilsch vortex tube?

Thanks for any help!
 
Science news on Phys.org
Spinnor said:
Can I argue that for very strong force F_max the gas in the upper half of the cylinder will expand and the gas in the lower half of the tube will compress so that there should initially be a temperature difference between the gas in top and the bottom of the cylinder?
Sure.
Spinnor said:
Is this in effect part of the physics behind the Ranque-Hilsch vortex tube?
It is related I think.
 
  • Like
Likes Spinnor
Back
Top