[jdkummer]

I am currently running a simulation with a rotating mesh, very similar to the mixer2D tutorial in order to test remaking the mesh.

I successfully ran the mixer2D case; however, with my new case, I get the following error very soon after starting the simulation:

--> 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 cfdTools/general/adjustPhi/adjustPhi.C at line 108.

FOAM exiting

If I go into the controlDict file and change the PISO nCorrectors to zero, then the simulation runs fine, so I do not believe it is a problem with the sliding interface.

I admit I am very new to Openfoam, so if anyone knows what this error is and how to fix the problem it would be greatly appreciated. Thanks

Joe Kummer

[hjasak]

This is an issed with the global mas tolerance and I've been fiddling with it for a while. The issue is that you can accumulate up to machine tolerance of error for each face in motion and the checking is very sensitive to total volume in the domain when the interface slides. Have a look at:

finiteVolume/cfdTools/general/adjustPhi/adjustPhi.C, around line 96. Currently, I am using:

scalar massCorr = 1.0;

if (mag(adjustableMassOut) > SMALL)
{
massCorr = (massIn - fixedMassOut)/adjustableMassOut;

else if (mag(fixedMassOut - massIn) > 1e-12*Foam::max(1.0, mag(massIn)))
{
FatalErrorIn
...}

and it's sort of fine (no problems thus far).

Hrv

[jdkummer]

This may seem like a silly questions, but I am not able to find the directory finiteVolume anywhere. I have to admit I am also new to Linux.

Also, once I make the changes, will I need to recompile anything? Thanks

[jdkummer]

Excuse that...I found the directory and file. But the second question still remains. After making changes to this file, do I need to recompile it?

[hjasak]

cd ~/OpenFOAM/OpeFOAM-1.3/src/finiteVolume/cfdTools/general/adjustPhi/adjustPhi.C

You will need to rebuild only the main library and it should recompile only this one file.

Read up the manual pages on "find" and "grep", e.g.

man find

or try:

foam
find . -type f -name adjustPhi.C -print

Hrv

[jdkummer]

Thank you, I will give it a try.

[jdkummer]

Once again they may seem silly, but how should I recompile the file?

I read the documentation on writing new applications, and it talks about using wmake. I found a script called Allwmake under the Openfoam-1.3/src directory, so I tried this. I think it is working, but I believe it is recompiling everything. You mentioned that I should only recompile the one file. How does one do this? Thanks.

Joe

[hjasak]

You need to read the documentation:

src
cd finiteVolume
wmake libso

Hrv

[jdkummer]

Thanks

[andreho]

Hello,

I have a similar problem. I have a model with a moving mesh (pimpleDyMFoam), where a rigid body oscillates (a rotating oscillation) in a computational domain. All outer boundaries are fixed value (0,0,0) for the velocity and zero gradient for the pressure. The moving wall boundary is fixed value (rotation) and zero gradient as well.

I receive the following error:



Continuity error cannot be removed by adjusting the outflow.
Please check the velocity boundary conditions and/or run potentialFoam to initialise the outflow.
Total flux : 0.0419322
Specified mass inflow : 8.7002e-11
Specified mass outflow : 4.94772e-10
Adjustable mass outflow : 0

From function adjustPhi(surfaceScalarField& phi, const volVectorField& U,const volScalarField& p
in file cfdTools/general/adjustPhi/adjustPhi.C at line 116.
FOAM exiting


How can this be? Inflow and outflow is the same since the oscillating body is completely surrounded by fluid and the outer boundaries have no flow at all.

More interesting, translation works fine. I also calculated the solution with non-moving mesh and used the solution as initial values for the simulation with moving mesh, but I received the exactly same error message with exactly the same values.


Does anybody has an idea how to solve this issue?

Many thanks in advance,

andreas

[wouter]

Hello All,

I get the same error message with interFoam where I am trying to fill a vessel, so I know that at the start there is a difference between mass inflow and mass outflow. (liquid in, gas out). How can I solve this?
I am using 1.6-ext with ubuntu 10.04

Thanks,
Wouter