| bytesurfer |
December 11, 2015 13:24 |
MRFSimpleFoam diverges (Pre-Processing errors?)
Hello community,
I have a problem with my MRFSimpleFoam case.
At first a bit about my problem:
For a class in university I have to simulate a stirred tank with a rushton turbine. We did the lid driven cavity case as an example and now we have to solve the tank ourselves.
I created my mesh in pointwise and exported it to OpenFoam. CheckMesh says that everything is okay, except a few non-orthogonal faces.
Code:
Create time
Create polyMesh for time = 0
Time = 0
Mesh stats
points: 487989
faces: 3384189
internal faces: 3303318
cells: 1504134
faces per cell: 4.44608
boundary patches: 6
point zones: 0
face zones: 1
cell zones: 1
Overall number of cells of each type:
hexahedra: 0
prisms: 631533
wedges: 0
pyramids: 39438
tet wedges: 0
tetrahedra: 833163
polyhedra: 0
Checking topology...
Boundary definition OK.
Cell to face addressing OK.
Point usage OK.
Upper triangular ordering OK.
Face vertices OK.
Number of regions: 1 (OK).
Checking patch topology for multiply connected surfaces...
Patch Faces Points Surface topology
Baffles 13722 6942 ok (non-closed singly connected)
Tank 11598 5848 ok (non-closed singly connected)
Top 7351 4883 ok (non-closed singly connected)
impeller 40568 20301 ok (non-closed singly connected)
shaft-rt 845 455 ok (non-closed singly connected)
shaft-st 6787 3426 ok (non-closed singly connected)
Checking geometry...
Overall domain bounding box (-0.15 -0.15 0) (0.15 0.15 0.3)
Mesh (non-empty, non-wedge) directions (1 1 1)
Mesh (non-empty) directions (1 1 1)
Boundary openness (1.34546e-18 -3.36675e-18 -5.92271e-17) OK.
Max cell openness = 5.1542e-15 OK.
Max aspect ratio = 376.953 OK.
Minimum face area = 7.1479e-12. Maximum face area = 0.000129353. Face area magnitudes OK.
Min volume = 5.17032e-16. Max volume = 4.46924e-07. Total volume = 0.0211778. Cell volumes OK.
Mesh non-orthogonality Max: 89.9581 average: 23.0521
*Number of severely non-orthogonal (> 70 degrees) faces: 43679.
Non-orthogonality check OK.
<<Writing 43679 non-orthogonal faces to set nonOrthoFaces
Face pyramids OK.
Max skewness = 2.46475 OK.
Coupled point location match (average 0) OK.
Mesh OK.
End
I tried to resolve my problem with the non-orthogonal faces, but so far nothing on that end.
Since I only did the cavity case, I tried to assemble the fvsolution, fvscheme and fvoptions files myself. I played a little bit with the algorithms and tried euler instead of steadyState, too.
Code:
FoamFile
{
version 2.0;
format ascii;
class dictionary;
location "system";
object fvSolution;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
solvers
{
p
{
solver PCG;
preconditioner
{
preconditioner GAMG;
smoother DICGaussSeidel;
nPreSweeps 0;
nPostSweeps 2;
nBottomSweeps 2;
cacheAgglomeration true;
nCellsInCoarsestLevel 1000;
agglomerator faceAreaPair;
mergeLevels 1;
}
tolerance 1e-5;
relTol 0.01;
}
"(U|k|epsilon)"
{
solver PBiCG;
preconditioner DILU;
tolerance 1e-05;
relTol 0.0;
}
Phi
{
solver GAMG;
smoother DIC;
cacheAgglomeration on;
agglomerator faceAreaPair;
nCellsInCoarsestLevel 10;
mergeLevels 1;
tolerance 1e-06;
relTol 0.01;
}
}
SIMPLE
{
nNonOrthogonalCorrectors 3;
pRefCell 0;
pRefValue 0;
residualControl
{
p 1e-4;
U 1e-4;
"(k|epsilon)" 1e-4;
}
}
potentialFlow
{
nNonOrthogonalCorrectors 10;
PhiRefCell 1;
PhiRefValue 0;
}
relaxationFactors
{
fields
{
p 0.3;
}
equations
{
U 0.5;
k 0.5;
epsilon 0.5;
}
}
Code:
FoamFile
{
version 2.0;
format ascii;
class dictionary;
location "system";
object fvSchemes;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
ddtSchemes
{
default steadyState;
}
gradSchemes
{
default Gauss linear;
grad(p) cellMDLimited Gauss linear 0.5;
grad(U) cellMDLimited Gauss linear 0.5;
}
divSchemes
{
default none;
// div(phi,U) bounded Gauss upwind;
div(phi,U) bounded Gauss linearUpwind grad(U);
div(phi,k) bounded Gauss upwind;
div(phi,epsilon) bounded Gauss upwind;
div((nuEff*dev(T(grad(U))))) Gauss linear;
}
laplacianSchemes
{
default Gauss linear limited 1.0;
laplacian((1|A(U)),p) Gauss linear limited 0.5;
laplacian(nuEff,U) Gauss linear limited 0.5;
laplacian(DkEff,k) Gauss linear limited 0.333;
laplacian(DepsilonEff,epsilon) Gauss linear limited 0.3333;
}
interpolationSchemes
{
default linear;
}
snGradSchemes
{
default corrected;
}
fluxRequired
{
default no;
p ;
Phi ;
}
Code:
FoamFile
{
version 2.0;
format ascii;
class dictionary;
location "system";
object fvOptions;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
MRF1
{
type MRFSource;
active true;
selectionMode cellZone;
cellZone rotor-cells;
MRFSourceCoeffs
{
active true;
origin (0 0 0);
axis (0 0 1);
omega -10,472;
}
}
Maybe I did something wrong in that area.
Here is the result file from SimpleFoam:
Code:
Create time
Create mesh for time = 0
Reading field p
Reading field U
Reading/calculating face flux field phi
Selecting incompressible transport model Newtonian
Selecting RAS turbulence model kEpsilon
kEpsilonCoeffs
{
Cmu 0.09;
C1 1.44;
C2 1.92;
sigmaEps 1.3;
}
Creating finite volume options from "system/fvOptions"
Selecting finite volume options model type MRFSource
Source: MRF1
- applying source for all time
- selecting cells using cellZone rotor-cells
- selected 670952 cell(s) with volume 0.000425687
SIMPLE: convergence criteria
field p tolerance 0.0001
field U tolerance 0.0001
field "(k|epsilon)" tolerance 0.0001
Starting time loop
Time = 0.005
DILUPBiCG: Solving for Ux, Initial residual = 1, Final residual = 3.12329e-07, No Iterations 4
DILUPBiCG: Solving for Uy, Initial residual = 1, Final residual = 3.19712e-07, No Iterations 4
DILUPBiCG: Solving for Uz, Initial residual = 1, Final residual = 1.30184e-06, No Iterations 4
GAMGPCG: Solving for p, Initial residual = 1, Final residual = 0.00466828, No Iterations 3
GAMGPCG: Solving for p, Initial residual = 0.809306, Final residual = 0.00262468, No Iterations 2
GAMGPCG: Solving for p, Initial residual = 0.116645, Final residual = 0.000305393, No Iterations 2
GAMGPCG: Solving for p, Initial residual = 0.0346045, Final residual = 8.29727e-05, No Iterations 2
time step continuity errors : sum local = 9.32531e-07, global = 8.45741e-21, cumulative = 8.45741e-21
DILUPBiCG: Solving for epsilon, Initial residual = 0.117342, Final residual = 7.0707e-07, No Iterations 3
DILUPBiCG: Solving for k, Initial residual = 1, Final residual = 1.18168e-07, No Iterations 5
ExecutionTime = 21.17 s ClockTime = 27 s
Time = 0.01
DILUPBiCG: Solving for Ux, Initial residual = 0.913458, Final residual = 6.58616e-07, No Iterations 4
DILUPBiCG: Solving for Uy, Initial residual = 0.913014, Final residual = 7.41462e-07, No Iterations 4
DILUPBiCG: Solving for Uz, Initial residual = 0.913583, Final residual = 6.82136e-07, No Iterations 4
GAMGPCG: Solving for p, Initial residual = 0.235286, Final residual = 0.00084983, No Iterations 3
GAMGPCG: Solving for p, Initial residual = 0.615328, Final residual = 0.00340317, No Iterations 3
GAMGPCG: Solving for p, Initial residual = 0.971477, Final residual = 0.00906469, No Iterations 2
GAMGPCG: Solving for p, Initial residual = 0.995672, Final residual = 0.00617046, No Iterations 2
time step continuity errors : sum local = 0.0281242, global = -5.23062e-17, cumulative = -5.22977e-17
DILUPBiCG: Solving for epsilon, Initial residual = 1, Final residual = 1.07123e-06, No Iterations 5
bounding epsilon, min: -28.7564 max: 2.04466e+15 average: 3.77328e+09
DILUPBiCG: Solving for k, Initial residual = 1, Final residual = 1.2268e-07, No Iterations 3
ExecutionTime = 36.44 s ClockTime = 43 s
Time = 0.015
DILUPBiCG: Solving for Ux, Initial residual = 0.561159, Final residual = 6.8168e-06, No Iterations 2
DILUPBiCG: Solving for Uy, Initial residual = 0.561325, Final residual = 6.80877e-06, No Iterations 2
DILUPBiCG: Solving for Uz, Initial residual = 0.561162, Final residual = 6.81625e-06, No Iterations 2
GAMGPCG: Solving for p, Initial residual = 0.999947, Final residual = 0.00903246, No Iterations 5
GAMGPCG: Solving for p, Initial residual = 1.74608e-05, Final residual = 7.51276e-07, No Iterations 1
GAMGPCG: Solving for p, Initial residual = 0.000884558, Final residual = 3.59299e-06, No Iterations 2
GAMGPCG: Solving for p, Initial residual = 0.00412373, Final residual = 1.64771e-05, No Iterations 2
time step continuity errors : sum local = 3.93065e+13, global = -0.0175471, cumulative = -0.0175471
DILUPBiCG: Solving for epsilon, Initial residual = 1, Final residual = 1.94567e-06, No Iterations 5
DILUPBiCG: Solving for k, Initial residual = 1, Final residual = 1.04978e-07, No Iterations 2
ExecutionTime = 50.71 s ClockTime = 58 s
Time = 0.02
DILUPBiCG: Solving for Ux, Initial residual = 0.0561779, Final residual = 4.60607e-07, No Iterations 2
DILUPBiCG: Solving for Uy, Initial residual = 0.325571, Final residual = 2.86478e-06, No Iterations 2
DILUPBiCG: Solving for Uz, Initial residual = 0.0501521, Final residual = 4.86382e-09, No Iterations 2
GAMGPCG: Solving for p, Initial residual = 1, Final residual = 494.301, No Iterations 1001
GAMGPCG: Solving for p, Initial residual = 1, Final residual = 1.40105e-14, No Iterations 1
GAMGPCG: Solving for p, Initial residual = 0.9441, Final residual = 1.72134e-15, No Iterations 1
GAMGPCG: Solving for p, Initial residual = 0.0874721, Final residual = 7.70611e-16, No Iterations 1
time step continuity errors : sum local = 9.57218e+39, global = -1.65747e+25, cumulative = -1.65747e+25
DILUPBiCG: Solving for epsilon, Initial residual = 1, Final residual = 8.76851e-06, No Iterations 16
DILUPBiCG: Solving for k, Initial residual = 9.07054e-22, Final residual = 9.07054e-22, No Iterations 0
ExecutionTime = 854.54 s ClockTime = 931 s
Time = 0.025
DILUPBiCG: Solving for Ux, Initial residual = 0.545841, Final residual = 8.00364e-06, No Iterations 44
DILUPBiCG: Solving for Uy, Initial residual = 0.545779, Final residual = 4.74215e-06, No Iterations 44
DILUPBiCG: Solving for Uz, Initial residual = 0.54569, Final residual = 3.80886e-06, No Iterations 43
Thank you very much for your help! |
