Thermodynamics of gas in very strong gravitational field.

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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
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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!
 
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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.
 
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