Falcon Heavy

Thread Starter

nsaspook

Joined Aug 27, 2009
13,313
Q. (Serious): what is the velocity at which pressurized gas particles expand in a vacuum of infinite volume?
https://articles.adsabs.harvard.edu//full/1966must.conf..269Y/0000269.000.html

A tricky question that depends on initial PE pressure (original volume of gas), jet size aperture and the level of vacuum.
https://www.physicsforums.com/threads/free-expansion-of-gas.687051/

I don't deal with rockets but I've seen a few vacuum implosions in ultra high vacuum chambers several meters long. The estimated wave velocities were supersonic judging on the damage seen.
 

joeyd999

Joined Jun 6, 2011
5,287
https://articles.adsabs.harvard.edu//full/1966must.conf..269Y/0000269.000.html

A tricky question that depends on initial PE pressure (original volume of gas), jet size aperture and the level of vacuum.
https://www.physicsforums.com/threads/free-expansion-of-gas.687051/

I don't deal with rockets but I've seen a few vacuum implosions in ultra high vacuum chambers several meters long. The estimated wave velocities were supersonic judging on the damage seen.
So, the final velocity of the gas molecules must possess a total kinetic energy equal to the original PE of the pressurized gas, yes?
 

joeyd999

Joined Jun 6, 2011
5,287
So, the final velocity of the gas molecules must possess a total kinetic energy equal to the original PE of the pressurized gas, yes?
Which is interesting in that the final velocity, given the same initial pressure, will be an inverse function of the molecular weight of the gas. Neat.
 

Thread Starter

nsaspook

Joined Aug 27, 2009
13,313
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