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openTom May 9, 2009 09:25

interFoam solver needs pdRefCell?
Hi Foamers,
i've got a question about the interFoam solver. I have implemented a new case in OpenFoam. I'm using a closed box (4 walls and empty frontAndBack) and when I'm trying to solve my case with the interFoam solver, i have to set pdRefCell and pdRefValue in the fvsolution file. Why is this neccessary? If i have a look in the damBreak test case, there isn't set a pdRefCell/pdRefValue, too. Is this because of the damBreak test case having an atmosphere boundary condition?

ngj May 10, 2009 09:14

Hi Tom (?)

If you are solving the poisson equation specifying only zeroGradient type boundary conditions, then in the mathematical sense there is a unique solution _plus_ an unknown constant. This constant can only be determined (obtain a truely unique solution), by specifying the pressure at an internal located point.
In the case of the damBreak case a Dirichlet boundary condition is specified for the pressure at the atmospheric boundary, hence it is not needed to specify pdRefCell/pdRef.

Best regards,


openTom May 10, 2009 10:20

Hi Niels,
All right. That makes sense.
Thank you.

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