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Problem with pressure equation in rhoSimpleFoam

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Old   July 10, 2017, 09:05
Default Problem with pressure equation in rhoSimpleFoam
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dario
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Hi all,
I'm trying to solve an external field around a 3D wing. The flow is at Mach = 0.78.
The checkMesh application seems to be ok:

Quote:
Checking geometry...
Overall domain bounding box (-39.54701387 -0.02841032651 -40.63372186) (46.72535601 50.17495664 40.1780381)
Mesh has 3 geometric (non-empty/wedge) directions (1 1 1)
Mesh has 3 solution (non-empty) directions (1 1 1)
Boundary openness (4.795358352e-17 -3.74681294e-17 1.258816993e-16) OK.
Max cell openness = 1.73712416e-15 OK.
Max aspect ratio = 115.5201724 OK.
Minimum face area = 1.338572813e-05. Maximum face area = 59.99552135. Face area magnitudes OK.
Min volume = 6.131690308e-07. Max volume = 49.41030061. Total volume = 174080.4162. Cell volumes OK.
Mesh non-orthogonality Max: 82.83259138 average: 21.70561315
*Number of severely non-orthogonal (> 70 degrees) faces: 101.
Non-orthogonality check OK.
<<Writing 101 non-orthogonal faces to set nonOrthoFaces
Face pyramids OK.
Max skewness = 1.967783537 OK.
Coupled point location match (average 0) OK.

Mesh OK.
by the way, when I try to solve the system, something strange happen with the p-equation: the residuals seems to be already converged at the first iteration (see image attached).

I tried to change the fvscheme and fvsolution, but nothing change. Here is what I'm using:

Quote:
ddtSchemes
{
default steadyState;
}

gradSchemes
{
default Gauss linear;
}

divSchemes
{
default none;

div(phi,U) bounded Gauss upwind;
div(((rho*nuEff)*dev2(T(grad(U))))) Gauss linear;
div(phi,e) bounded Gauss upwind;
div(phi,epsilon) bounded Gauss upwind;
div(phi,k) bounded Gauss upwind;
div(phid,p) bounded Gauss upwind;

div(phi,Ekp) bounded Gauss upwind;
div((phi|interpolate(rho)),p) bounded Gauss upwind;
}

laplacianSchemes
{
default Gauss linear corrected;
}

interpolationSchemes
{
default linear;
}

snGradSchemes
{
default corrected;
}
Quote:
solvers
{
p
{
solver GAMG;
tolerance 1e-12;
relTol 0.1;
smoother GaussSeidel;
nCellsInCoarsestLevel 20;
}

"(U|e|k|epsilon)"
{
solver GAMG;
tolerance 1e-08;
relTol 0.01;
smoother GaussSeidel;
nCellsInCoarsestLevel 20;
}
}

SIMPLE
{
nNonOrthogonalCorrectors 0;
rhoMin 0.1;
rhoMax 2.0;
transonic yes;
consistent yes;

residualControl
{
p 1e-5;
U 1e-5;
e 1e-5;

// possibly check turbulence fields
"(k|epsilon|omega)" 1e-4;
}
}

relaxationFactors
{
fields
{
p 0.3;
rho 0.7;
T 0.7;
}
equations
{
p 0.7;
U 0.7;
e 0.7;
k 0.7;
epsilon 0.7;
T 0.7;
}
}
Running the simulation for 100 steps all the others residuals go under 10e-5, while pressure residual is static. Obviously the solution of the pressure is wrong, in paraFoam I see a uniform field for all time steps, and a non uniform field for velocity.
Do you know what could be wrong?

Thanks
Attached Images
File Type: png Screenshot from 2017-07-10 13-59-33.png (25.2 KB, 21 views)
Attached Files
File Type: txt log.rhoSimpleFoam.txt (9.7 KB, 4 views)
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