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Propeller cavitation with non condensable gas(first constant property then ideal gas)

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Old   February 9, 2015, 05:47
Default Propeller cavitation with non condensable gas(first constant property then ideal gas)
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Behrooz Jamshidi
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Hi
Im modeling cavitation on a propeller with a constant volume fraction of air.After a procedure I got converged solution with reasonable results.
Now when I change air to ideal gas (with isothermal heat transfer) or define an expression for variable density with the previous run as initial value, I get overflow error on the first time step.
B.C:velocity inlet and opening with static pressure.
tstep=0.0001

Ive also decreased time step to 10e-9 which didnt help.
Decreasing relaxation factors caused overflow happen later(on 6th tstep)
Any idea?
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Old   February 9, 2015, 06:23
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Glenn Horrocks
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I have attempted a similar simulation previously and never got it to work either. I never looked into it very hard, but you can expect to have a hard time getting this to converge (as you have found). I can only recommend trying some of the solver expert parameters and other solver settings and see if they help, otherwise contact ANSYS and see if they can help you.
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