- #1
ozmac
- 25
- 0
I have what seems like a straight forward question, but am unable to find a formula.
The question originates from my previous topic which was trolled: https://www.physicsforums.com/threads/blowing-up-a-balloon-using-centrifugal-force.848892/
Basically I have a 1.5m hollow length of 10mm tube and due to centrifugal/centripetal force, at one closed end of the tube the acceleration is 24g, and at the other open end it is zero. The gradient is linear (Ac=w^2*r)
I'm trying to calculate the pressure of the gas at the closed end of the tube.
As the air is compressible, you can't use p = h ρ g because the density of the air is a variable dependent upon the pressure. But the pressure calculation here uses the density. There must be a different formula which uses the molecular mass of air. But even then, the amount of molecules of air in the tube is dependent upon the pressure, as with the air that is accelerated towards the closed end of the tube, this results in additional air being sucked in the open end of the tube.
There are so many things going on dependent on each other, all the while with a hugely variable 'gravity' so I just don't know where to begin. The easiest way would be to put a pressure switch at the end of the tube, but I'd prefer if there was also a way to calculate this also.
Thanks
The question originates from my previous topic which was trolled: https://www.physicsforums.com/threads/blowing-up-a-balloon-using-centrifugal-force.848892/
Basically I have a 1.5m hollow length of 10mm tube and due to centrifugal/centripetal force, at one closed end of the tube the acceleration is 24g, and at the other open end it is zero. The gradient is linear (Ac=w^2*r)
I'm trying to calculate the pressure of the gas at the closed end of the tube.
As the air is compressible, you can't use p = h ρ g because the density of the air is a variable dependent upon the pressure. But the pressure calculation here uses the density. There must be a different formula which uses the molecular mass of air. But even then, the amount of molecules of air in the tube is dependent upon the pressure, as with the air that is accelerated towards the closed end of the tube, this results in additional air being sucked in the open end of the tube.
There are so many things going on dependent on each other, all the while with a hugely variable 'gravity' so I just don't know where to begin. The easiest way would be to put a pressure switch at the end of the tube, but I'd prefer if there was also a way to calculate this also.
Thanks