- **OpenFOAM Running, Solving & CFD**
(*https://www.cfd-online.com/Forums/openfoam-solving/*)

- - **interFoam solver needs pdRefCell?**
(*https://www.cfd-online.com/Forums/openfoam-solving/64393-interfoam-solver-needs-pdrefcell.html*)

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? Thanks |

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, Niels |

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

All times are GMT -4. The time now is 21:15. |