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How to get rid of the defaultFaces, Courant number diverge.

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Old   April 30, 2011, 23:10
Default How to get rid of the defaultFaces, Courant number diverge.
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Guifan Li
Join Date: Apr 2011
Location: New York City, U.S.
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Dear all,

I want to simulate an artery with bifurcation. After using Gmsh to generate a mesh file and convert it to openfoam.

You can see the screenshot in attachment, there are one "inlet", one "straight_outlet", one "bent_outlet". And there are some defaultFaces at the interaction.

When I using icoFoam to run the file, the program will be interupted because courant number become to large.

I am just wondering it that because the defaultFaces at interaction block the fluids entering the bifurcation(daughter arteries)?

How can I get rid of the defaultFaces, I mean delete them( I can not delete it in gmsh, and delete them in polyMesh/boundary as well)?


Here are my p and U file.

U
dimensions [0 1 -1 0 0 0 0];

internalField uniform (0 0 0);

boundaryField
{
artery_wall
{
type fixedValue;
value uniform (0 0 0);
}
inlet
{
type fixedValue;
value uniform (0 0 -0.11);
}
straight_outlet
{
type zeroGradient;
}
bent_outlet
{
type zeroGradient;
}

}

p
dimensions [0 2 -2 0 0 0 0];
internalField uniform 0;
boundaryField
{
artery_wall
{
type zeroGradient;
}
inlet
{
type zeroGradient;
}
straight_outlet
{
type fixedValue;
value uniform 0;
}
bent_outlet
{
type fixedValue;
value uniform 0;
}
}
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Old   April 30, 2011, 23:13
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Guifan Li
Join Date: Apr 2011
Location: New York City, U.S.
Posts: 96
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It may be because of the other problems which I haven't figure out.
Here is my controlDict file
application implicitFoam;

startFrom latestTime;

startTime 0;

stopAt endTime;

endTime 0.1;

deltaT 0.001;

writeControl timeStep;

writeInterval 10;

purgeWrite 0;

writeFormat ascii;

writePrecision 6;

writeCompression uncompressed;

timeFormat general;

timePrecision 6;

runTimeModifiable yes;

libs ("ResistanceBC_relaxed.so");


the length of the artery is around 0.01-0.03 m.

regards
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