[sam.ho]

Hi ,

I am simulating a steady state turbulent flow inside a valve using simpleFOAM.
The valve has 1 inlet and 4 outlets
Boundary Conditions INLET OUTLET
Velocity 0.27 m/s zeroGradient
pressure freestreamPressure fixedvalue 0

and all other boundaries like spring, spring support and valve body as no-slip condition and zero gradient pressure condition.

I am getting an error which has been attached with this post. Please look in to the problem and let me know how to avoid this error.

[Antimony]

Hi,

Your continuity error is basically 1e19! Your simulation has diverged. Check your boundary conditions. Or perhaps post the case here.

Regards,

Antimony

[sam.ho]

Hi,

I just switched off the turbulence model and run the case( with same boundary conditions) . Its running fine with continuity error decreasing as we can see in the attachment .
But why its not running when we switch on the turbulence model ?

Any suggestions ?

[Antimony]

Hi,

May I ask why is the p equation being solved three times within the same time step? Can you post your case without the mesh here?

Regards,

Antimony

[sam.ho]

[FoamFile
{
version 2.0;
format ascii;
class dictionary;
location "system";
object controlDict;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

application simpleFoam;

startFrom latestTime;

startTime 0;

stopAt endTime;

endTime 100;

deltaT 10e-6;

writeControl timeStep;

writeInterval 10000;

purgeWrite 0;

writeFormat ascii;

writePrecision 6;

writeCompression off;

timeFormat general;

timePrecision 8;

runTimeModifiable true;]

[FoamFile
{
version 2.0;
format ascii;
class dictionary;
location "system";
object fvSchemes;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

ddtSchemes
{
default steadyState;
}

gradSchemes
{
default Gauss linear;
grad(p) Gauss linear;
grad(U) Gauss linear;
}

divSchemes
{
default none;
div(phi,U) bounded Gauss upwind;
div(phi,k) bounded Gauss upwind;
div(phi,epsilon) bounded Gauss upwind;
div(phi,R) bounded Gauss upwind;
div(R) Gauss linear;
div(phi,nuTilda) bounded Gauss upwind;
div((nuEff*dev(T(grad(U))))) Gauss linear;
}

laplacianSchemes
{
default none;
laplacian(nuEff,U) Gauss linear corrected;
laplacian((1|A(U)),p) Gauss linear corrected;
laplacian(DkEff,k) Gauss linear corrected;
laplacian(DepsilonEff,epsilon) Gauss linear corrected;
laplacian(DREff,R) Gauss linear corrected;
laplacian(DnuTildaEff,nuTilda) Gauss linear corrected;
}

interpolationSchemes
{
default linear;
interpolate(U) linear;
}

snGradSchemes
{
default corrected;
}

fluxRequired
{
default no;
p ;
}
// ************************************************** *********************** //]

[FoamFile
{
version 2.0;
format ascii;
class dictionary;
location "system";
object fvSolution;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

solvers
{
p
{
solver PCG;
preconditioner DIC;
tolerance 1e-06;
relTol 0.01;
}

U
{
solver PBiCG;
preconditioner DILU;
tolerance 1e-05;
relTol 0.1;
}

k
{
solver PBiCG;
preconditioner DILU;
tolerance 1e-05;
relTol 0.1;
}

epsilon
{
solver PBiCG;
preconditioner DILU;
tolerance 1e-05;
relTol 0.1;
}

R
{
solver PBiCG;
preconditioner DILU;
tolerance 1e-05;
relTol 0.1;
}

nuTilda
{
solver PBiCG;
preconditioner DILU;
tolerance 1e-05;
relTol 0.1;
}
}

SIMPLE
{
nNonOrthogonalCorrectors 2;
pRefCell 101;
pRefCell 58;
pRefCell 767;
pRefCell 527;
pRefValue 0;
residualControl
{
p 1e-2;
U 1e-3;
"(k|epsilon|omega)" 1e-3;
}
}

relaxationFactors
{
fields
{
p 0.3;
}
equations
{
U 0.5;
k 0.5;
epsilon 0.5;
R 0.5;
nuTilda 0.5;
}
}


// ************************************************** *********************** //]