[jinyaqing]

Hi, everyone:
I am trying to run dynamic mesh case in pimpleDyMFoam, but after running one step, I always encounter this problem:
updateCoeffs(const scalarField& snGradp) MUST be called before updateCoeffs() or evaluate() to set the boundary gradient

Does anyone meet similar problems before? Thank you very much.

[acflip]

Hello,
Are you using a type fixedFluxPressure for a pressure boundary condition? Maybe try switching to a zeroGradient boundary condition in pressure and see if the error goes away.
Good luck

[gaza]

Thanks it helped.

[SimOF]

I have the same problem in simpleFoam. Using zeroGradient works.
But my case is that I want to simulate the pressure drop in a bifurcation of tubes with a given massflow through the tube. So, as far a I understand fixedFluxPressure is the boundary condition I should use.
How can I fix the case to use fixedFluxPressure?

[Kenmaster]

Did you solve this?

[Kenmaster]

Originally Posted by acflip

Hello,
Are you using a type fixedFluxPressure for a pressure boundary condition? Maybe try switching to a zeroGradient boundary condition in pressure and see if the error goes away.
Good luck

I am in the same problem with fixedFluxPressure boundary conditions but changing the BC to zeroGradient does not work still

[Voulet]

Hello. I've the same error problem here with ofv2106.

inlet
{
    type            fixedFluxPressure;
    value           uniform 0;
}

outlet
{
     type            PrimalPressureOutlet;
     p0              uniform 0.;
}

paroiAdiabatique
{
    type            fixedFluxPressure;
    value           uniform 0;
}

paroiChaude
{
    type            fixedFluxPressure;
    value           uniform 0;
}

Does anyone has an idea on how solve this ? What does the error means ?

[Raphael_Santos]

An old post, but, check if you wrote fixedFluxPressure in another propertie, as velocity or temperature, etc.