[liugx212]

Dear friend,

When I run icoFoam with 92*92*92 volume, I got the error here. I want to say it is ok if I set the internal U in 2 or 3 direction. But if only X direction it is error as follows. Could anybody can help me?

Thank you very much.
Best wishes,
Guoxiang


The error massage:

Create mesh for time = 0

Reading field nu

Reading field p

Reading field U

Reading/calculating face flux field phi


Starting time loop

Time = 0.005

Mean and max Courant Numbers = 0 0.05
BICCG: Solving for Ux, Initial residual = 1, Final residual = 5.04614e-12, No Iterations 1


--> FOAM FATAL ERROR : Continuity error cannot be removed by adjusting the outflow.
Please check the velocity boundary conditions and/or run potentialFoam to initialise the outflow.
From function adjustPhi(surfaceScalarField& phi, const volVectorField& U,const volScalarField& p
in file adjustPhi/adjustPhi.C at line 108.

FOAM exiting

[mattijs]

I assume this is the lid-driven cavity case? How you initialize the internal field does not matter too much. Just means more work (probably) to get to the final state.

Did you change the 'empty' boundary condition on the front and back? Empty should only be used if you can guarantee there is no flow in that (z) direction.

For a 3D case (since you have cells in the z direction) this will not be the case and you will have to specify a valid boundary condition there.

[liugx212]

Hi Mattijs Janssens:

Thanks for your help.

Yes, I use the cavity case of icoFoam. I have checked that my mesh is 3D which left side is inlet, right is outlet. up front and back are all atmosphere while the buttom is fixed wall. Also, I change the "nu" parameter as the field which is read from nu file in initial procedure. I set zeroGradient to U in outlet and atmosphere patchs. And initial U in inlet as a speed. Of cource, the fixedwall must be zero. My question is that I only want to set the initial speed of U in X direction. But when I set only X, the error as above. Could you please give me more help please?

Thanks a lot.
Guoxiang

[liugx212]

Hi friend:

I got it. Why the errors like this? if the value of the inlet and movingwall are same. That`s ok. Otherwise, the error like above.

But here, I have another question. In my case, I set the inlet and movingwall. I want to set the different values for them respectively. Could any friend help me this matter please?

Thanks advanced.
Guoxiang