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High Mach Number Flow - Gas Expanding Into Vacuum

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The geometry I modeled can be thought of as a straw into a 'large' chamber in the 2D-axisymmetric space dimension. The idea is to simulate gas flow into a vacuum chamber through a simple nozzle. I have been unable to get a solution to converge and I'm curious if anyone else has tried to simulate a similar configuration and has experienced problems with external flow when using the High Mach Number Flow module? I have varied the mesh size, initial conditions, the 'vacuum chamber' size, etc. to no avail. The only instance that leads to convergence on a solution is when the 'vacuum chamber' radius is made narrow enough so that the flow could be considered internal.

Any help that you could provide would be greatly appreciated.

1 Reply Last Post 11.01.2012, 15:43 GMT-5
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Hello Kettu

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Posted: 1 decade ago 11.01.2012, 15:43 GMT-5
I'm trying to do the same thing and am having similar problems. Daniel Smith of COMSOL told me that he doesn't think COMSOL Multiphysics can be used in this way. Have you tried contacting COMSOL directly about this? What did they say?
I'm trying to do the same thing and am having similar problems. Daniel Smith of COMSOL told me that he doesn't think COMSOL Multiphysics can be used in this way. Have you tried contacting COMSOL directly about this? What did they say?

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