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- - **Pressure definition in OF 2.0.1 (simpleFoam etc.)**
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Pressure definition in OF 2.0.1 (simpleFoam etc.)Hi,
Does anyone know what is pressure in OF2.0.1 for solver like SimpleFOAM?I have read that in previous versions of the code it was in fact Pstatic-rho*g*h, than in another version it was just Pstatic/rho. What is the actual statement for OF 2.0.1? The source of my question is simple: Consider a water box. you model inlet and outlet. If the outlet is at the bottom (i.e.altitude is lower than the inlet) what BC do I define for pressure at the outlet???If P stands for p/rho, I have to calculate the hydrostatic pressure at he bottom. If p stands fo p/rho-g*h: I just have to put P=0. Thanks for you help. Regards, Miles P.S;: I have found post on the subject but it was for older version as OF 1.7 |

Quote:
For simpleFoam it is a relative pressure related to a reference value. If you look at the creatFields.H and Peqn.H in the simpleFoam solver that might help. Dan |

You are confusing compressible and incompressible solvers. As far as I know, all the incompressible solvers in OF (like simpleFoam or pisoFoam), in all the releases (at least from the 1.6 to the 2.0.1, including the -dev/-ext ones), solve for the kinematic relative pressure, i. e. for p/rho (if rho is a constant, defining the pressure source term in the momentum equation as -1/rho*grad(p) or as -grad(p/rho) is equivalent). For the compressible solvers, things are not so established between different releases (honestly i really can't understand why), as for example in the 1.6 release a solver like rhoSimpleFoam assumes the static pressure as the dependent variable, while in the 1.7.0/1/x (and I think also in the 2.0.0/1/x family) the dependent variable is p-rho*g*h.
Hope this helps V. |

thanks for your replies
regards miles |

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