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-   -   Setting 'lowest pressure' pMin in compressibleInterFoam (http://www.cfd-online.com/Forums/openfoam/70686-setting-lowest-pressure-pmin-compressibleinterfoam.html)

kjetil December 2, 2009 10:49

Setting 'lowest pressure' pMin in compressibleInterFoam
 
Dear foamers,

the only thing remaining in my university term project, is to get get my water-air simulation from solver interFoam to the compressibleInterFoam. I have searched for info on how to use the compressible solver, but nothing of any use exists. My main problem is that setting the pressure pMin to a fixed value, the internal pressure fluctuates constantly/periodically - and in turn so does the velocity field. Does anybody have any hints at all to what to set pMin to, to get a stable simulation going? And what is the purpose of this pMin in the first place?

Thank you.

Marta April 21, 2010 13:30

Hi! Do you know how to set the pMin parameter correctly depending on the case you are solving? How does it affect the solution exactly?

Thanks

Marta

kjetil April 21, 2010 17:00

Hi Marta
unfortunately I didn't get an answer to this - but you might try to set it to zero or something close to zero, as 10E-6 or around that.

So, I too wish that someone could elaborate on the use of this pMin.

flowman April 21, 2010 20:40

Hi Kjetil,

compressibleInterFoam uses an equation of state: rho=p*psi. For isothermal expansion psi=1/RT. The value of the minimum pressure, pmin, must be set to something greater than zero to ensure the equation of state returns a density greater than zero to the solver.

See this thread for more info on compressibleInterFoam.

What type of problem are you trying to solve? Are you sure this equation of state is appropriate?


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