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High Courant Number @ icoFoam

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Old   December 28, 2011, 12:01
Post High Courant Number @ icoFoam
  #1
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Patrick Pazour
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Dear Foamers!

I designed a raw tetra mesh for a first view over the geometry. I wanted to test the flow with icoFoam. Unfortunately the courant number explodes after a few timesteps. Do you have any ideas how to get this work? Thanks a lot!

checkMesh:
Code:
Exec   : checkMesh
Date   : Dec 29 2011
Time   : 12:51:33
Host   : ubuntu
PID    : 4305
Case   : /home/ubuntu/OpenFOAM/ubuntu-1.5-dev/run/duese_3_tet_icofoam
nProcs : 1

// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
Create time

Create polyMesh for time = constant

Time = constant

Mesh stats
    points:           17575
    faces:            173802
    internal faces:   159746
    cells:            83387
    boundary patches: 4
    point zones:      0
    face zones:       0
    cell zones:       0

Number of cells of each type: 
    hexahedra:     0
    prisms:        0
    wedges:        0
    pyramids:      0
    tet wedges:    0
    tetrahedra:    83387
    polyhedra:     0

Checking topology...
    Boundary definition 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                  
    ColdWall            3374     1772     ok (non-closed singly connected)  
    HotWall             10453    5279     ok (non-closed singly connected)  
    Inlet               93       60       ok (non-closed singly connected)  
    Outlet              136      89       ok (non-closed singly connected)  

Checking geometry...
    This is a 3-D mesh
    Overall domain bounding box (-0.04 -0.0199997 -0.14) (0.02 0.0199993 0)
    Mesh (non-empty) directions (1 1 1)
    Mesh (non-empty, non-wedge) dimensions 3
    Boundary openness (1.76704e-19 2.54345e-19 4.48772e-20) Threshold = 1e-06 OK.
    Max cell openness = 1.54305e-16 OK.
    Max aspect ratio = 12.3272 OK.
    Minumum face area = 1.59421e-07. Maximum face area = 5.57485e-06.  Face area magnitudes OK.
    Min volume = 4.23187e-11. Max volume = 3.34644e-09.  Total volume = 8.00739e-05.  Cell volumes OK.
    Mesh non-orthogonality Max: 58.8765 average: 19.8095 Threshold = 70
    Non-orthogonality check OK.
    Face pyramids OK.
    Max skewness = 0.813531 OK.

Mesh OK.

End
fvSolution:
Code:
FoamFile
{
    version     2.0;
    format      ascii;
    class       dictionary;
    object      fvSolution;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

solvers
{
    p PCG
    {
        preconditioner   DIC;
        tolerance        1e-06;
        relTol           0;
    };

    U PBiCG
    {
        preconditioner   DILU;
        tolerance        1e-05;
        relTol           0;
    };
}

PISO
{
    nCorrectors     2;
    nNonOrthogonalCorrectors 1;
    pRefCell        0;
    pRefValue       0;
}
controlDict:
Code:
FoamFile
{
    version     2.0;
    format      ascii;
    class       dictionary;
    object      controlDict;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

application icoFoam;

startFrom       startTime;

startTime       0;

stopAt          endTime;

endTime         2;

deltaT          0.02;

writeControl    timeStep;

writeInterval   20;

purgeWrite      0;

writeFormat     ascii;

writePrecision  6;

writeCompression uncompressed;

timeFormat      general;

timePrecision   6;

runTimeModifiable yes;

adjustTimeStep  no;

Last edited by Artex85; December 29, 2011 at 09:38. Reason: update mesh and controlDict
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Old   December 28, 2011, 12:09
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What is the value of your Courant number? Have you tried a smaller time step?
You have turned off the adjustable time step by the way, maybe this could help if it was on.
Could you post the log file?
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Old   December 29, 2011, 09:50
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Patrick Pazour
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Hello anon_a!

Thanks for your quick reply, here is the log file:

Code:
Exec   : icoFoam
Date   : Dec 29 2011
Time   : 13:36:10
Host   : ubuntu
PID    : 5099
Case   : /home/ubuntu/OpenFOAM/ubuntu-1.5-dev/run/duese_3_tet_icofoam
nProcs : 1

// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
Create time

Create mesh for time = 0

Reading transportProperties

Reading field p

Reading field U

Reading/calculating face flux field phi


Starting time loop

Time = 0.02

Courant Number mean: 0 max: 0 velocity magnitude: 0
PBiCG:  Solving for Ux, Initial residual = 0, Final residual = 0, No Iterations 0
PBiCG:  Solving for Uy, Initial residual = 0, Final residual = 0, No Iterations 0
PBiCG:  Solving for Uz, Initial residual = 1, Final residual = 7.92461e-06, No Iterations 42
PCG:  Solving for p, Initial residual = 1, Final residual = 8.51221e-07, No Iterations 484
PCG:  Solving for p, Initial residual = 0.102054, Final residual = 9.82929e-07, No Iterations 459
time step continuity errors : sum local = 1.31195e-07, global = -3.07613e-10, cumulative = -3.07613e-10
PCG:  Solving for p, Initial residual = 0.054511, Final residual = 8.62196e-07, No Iterations 472
PCG:  Solving for p, Initial residual = 0.466713, Final residual = 8.97311e-07, No Iterations 467
time step continuity errors : sum local = 2.20975e-08, global = 1.92533e-11, cumulative = -2.88359e-10
ExecutionTime = 16.7 s  ClockTime = 17 s

Time = 0.04

Courant Number mean: 0.00506339 max: 3.82497 velocity magnitude: 0.0552267
PBiCG:  Solving for Ux, Initial residual = 0.748645, Final residual = 8.16663e-06, No Iterations 31
PBiCG:  Solving for Uy, Initial residual = 0.771322, Final residual = 9.49122e-06, No Iterations 34
PBiCG:  Solving for Uz, Initial residual = 0.6344, Final residual = 8.92808e-06, No Iterations 39
PCG:  Solving for p, Initial residual = 0.602528, Final residual = 8.92601e-07, No Iterations 488
PCG:  Solving for p, Initial residual = 0.110327, Final residual = 8.24463e-07, No Iterations 459
time step continuity errors : sum local = 5.43346e-07, global = 8.05496e-10, cumulative = 5.17137e-10
PCG:  Solving for p, Initial residual = 0.0449353, Final residual = 8.84106e-07, No Iterations 470
PCG:  Solving for p, Initial residual = 0.461692, Final residual = 8.98988e-07, No Iterations 466
time step continuity errors : sum local = 1.19582e-07, global = -1.29784e-10, cumulative = 3.87353e-10
ExecutionTime = 34.37 s  ClockTime = 34 s

Time = 0.06

Courant Number mean: 0.0263615 max: 13.485 velocity magnitude: 0.19658
PBiCG:  Solving for Ux, Initial residual = 0.764436, Final residual = 9.74761e-06, No Iterations 34
PBiCG:  Solving for Uy, Initial residual = 0.778582, Final residual = 9.481e-06, No Iterations 37
PBiCG:  Solving for Uz, Initial residual = 0.645542, Final residual = 7.43444e-06, No Iterations 40
PCG:  Solving for p, Initial residual = 0.60749, Final residual = 8.64835e-07, No Iterations 488
PCG:  Solving for p, Initial residual = 0.129048, Final residual = 8.77098e-07, No Iterations 457
time step continuity errors : sum local = 3.23187e-06, global = -1.31075e-09, cumulative = -9.234e-10
PCG:  Solving for p, Initial residual = 0.0464013, Final residual = 9.64245e-07, No Iterations 468
PCG:  Solving for p, Initial residual = 0.490751, Final residual = 9.75743e-07, No Iterations 464
time step continuity errors : sum local = 8.02591e-07, global = 2.05433e-09, cumulative = 1.13093e-09
ExecutionTime = 52.24 s  ClockTime = 52 s

Time = 0.08

Courant Number mean: 0.17455 max: 55.7621 velocity magnitude: 0.812884
PBiCG:  Solving for Ux, Initial residual = 0.775338, Final residual = 9.18494e-06, No Iterations 36
PBiCG:  Solving for Uy, Initial residual = 0.780003, Final residual = 8.83473e-06, No Iterations 38
PBiCG:  Solving for Uz, Initial residual = 0.649195, Final residual = 7.62692e-06, No Iterations 40
PCG:  Solving for p, Initial residual = 0.661197, Final residual = 9.82732e-07, No Iterations 479
PCG:  Solving for p, Initial residual = 0.163826, Final residual = 9.35047e-07, No Iterations 442
time step continuity errors : sum local = 2.31072e-05, global = 1.43139e-07, cumulative = 1.4427e-07
PCG:  Solving for p, Initial residual = 0.0544162, Final residual = 9.93518e-07, No Iterations 465
PCG:  Solving for p, Initial residual = 0.535228, Final residual = 9.42873e-07, No Iterations 448
time step continuity errors : sum local = 6.10979e-06, global = -3.08389e-08, cumulative = 1.13431e-07
ExecutionTime = 69.79 s  ClockTime = 70 s

Time = 0.1

Courant Number mean: 1.52184 max: 251.177 velocity magnitude: 3.66159
PBiCG:  Solving for Ux, Initial residual = 0.785002, Final residual = 7.78131e-06, No Iterations 37
PBiCG:  Solving for Uy, Initial residual = 0.775493, Final residual = 7.00292e-06, No Iterations 38
PBiCG:  Solving for Uz, Initial residual = 0.653513, Final residual = 7.65689e-06, No Iterations 39
PCG:  Solving for p, Initial residual = 0.73722, Final residual = 8.38555e-07, No Iterations 487
PCG:  Solving for p, Initial residual = 0.210158, Final residual = 8.81948e-07, No Iterations 458
time step continuity errors : sum local = 0.000179504, global = 6.47978e-09, cumulative = 1.19911e-07
PCG:  Solving for p, Initial residual = 0.0671591, Final residual = 9.26519e-07, No Iterations 469
PCG:  Solving for p, Initial residual = 0.577796, Final residual = 8.43418e-07, No Iterations 464
time step continuity errors : sum local = 5.39014e-05, global = 3.38347e-08, cumulative = 1.53746e-07
ExecutionTime = 88.14 s  ClockTime = 88 s

Time = 0.12

Courant Number mean: 15.771 max: 1213.58 velocity magnitude: 17.2683
PBiCG:  Solving for Ux, Initial residual = 0.791247, Final residual = 4.09263e-06, No Iterations 47
PBiCG:  Solving for Uy, Initial residual = 0.768959, Final residual = 1.95723e-06, No Iterations 53
PBiCG:  Solving for Uz, Initial residual = 0.660241, Final residual = 7.56799e-06, No Iterations 53
PCG:  Solving for p, Initial residual = 0.809628, Final residual = 8.35623e-07, No Iterations 481
PCG:  Solving for p, Initial residual = 0.270383, Final residual = 9.78329e-07, No Iterations 459
time step continuity errors : sum local = 0.00202547, global = 2.30268e-06, cumulative = 2.45642e-06
PCG:  Solving for p, Initial residual = 0.0840898, Final residual = 8.179e-07, No Iterations 468
PCG:  Solving for p, Initial residual = 0.611435, Final residual = 9.48164e-07, No Iterations 464
time step continuity errors : sum local = 0.000754444, global = -2.30185e-07, cumulative = 2.22624e-06
ExecutionTime = 107.21 s  ClockTime = 107 s

Time = 0.14

Courant Number mean: 203.818 max: 6315.59 velocity magnitude: 144.106
PBiCG:  Solving for Ux, Initial residual = 0.799529, Final residual = 7.23114e-06, No Iterations 118
PBiCG:  Solving for Uy, Initial residual = 0.768657, Final residual = 8.52382e-06, No Iterations 119
PBiCG:  Solving for Uz, Initial residual = 0.67574, Final residual = 6.44984e-06, No Iterations 123
PCG:  Solving for p, Initial residual = 0.644255, Final residual = 9.53304e-07, No Iterations 501
PCG:  Solving for p, Initial residual = 0.124882, Final residual = 8.26806e-07, No Iterations 468
time step continuity errors : sum local = 0.0255069, global = -5.32141e-06, cumulative = -3.09518e-06
PCG:  Solving for p, Initial residual = 0.0625569, Final residual = 9.64602e-07, No Iterations 485
PCG:  Solving for p, Initial residual = 0.476678, Final residual = 9.36606e-07, No Iterations 483
time step continuity errors : sum local = 0.00664253, global = -2.03334e-05, cumulative = -2.34285e-05
ExecutionTime = 134.23 s  ClockTime = 134 s

Time = 0.16

Courant Number mean: 1224.81 max: 5.8799e+06 velocity magnitude: 95137.2
PBiCG:  Solving for Ux, Initial residual = 0.995393, Final residual = 0.0200732, No Iterations 1000
PBiCG:  Solving for Uy, Initial residual = 0.991433, Final residual = 0.307995, No Iterations 1000
PBiCG:  Solving for Uz, Initial residual = 0.985122, Final residual = 0.0269352, No Iterations 1000
PCG:  Solving for p, Initial residual = 0.929687, Final residual = 11.7345, No Iterations 1000
PCG:  Solving for p, Initial residual = 0.794915, Final residual = 2.26295, No Iterations 1000
time step continuity errors : sum local = 3.50337e+06, global = 10532.6, cumulative = 10532.6
PCG:  Solving for p, Initial residual = 0.969994, Final residual = 1.9792, No Iterations 1000
PCG:  Solving for p, Initial residual = 0.680809, Final residual = 4.05222, No Iterations 1000
time step continuity errors : sum local = 1.599e+09, global = 1.22747e+07, cumulative = 1.22852e+07
ExecutionTime = 238.53 s  ClockTime = 239 s

Time = 0.18

Courant Number mean: 9.19732e+08 max: 1.85522e+12 velocity magnitude: 7.06915e+10
PBiCG:  Solving for Ux, Initial residual = 0.999745, Final residual = 9.62717, No Iterations 1000
PBiCG:  Solving for Uy, Initial residual = 0.999748, Final residual = 10.851, No Iterations 1000
PBiCG:  Solving for Uz, Initial residual = 0.999861, Final residual = 2.88039, No Iterations 1000
PCG:  Solving for p, Initial residual = 1, Final residual = 196.18, No Iterations 1000
PCG:  Solving for p, Initial residual = 0.843622, Final residual = 5.02074, No Iterations 1000
time step continuity errors : sum local = 2.12167e+18, global = 4.6608e+09, cumulative = 4.67308e+09
PCG:  Solving for p, Initial residual = 0.922669, Final residual = 2.7607, No Iterations 1000
PCG:  Solving for p, Initial residual = 0.873783, Final residual = 3.07253, No Iterations 1000
time step continuity errors : sum local = 3.67336e+20, global = 4.99835e+15, cumulative = 4.99835e+15
ExecutionTime = 341.26 s  ClockTime = 341 s

Time = 0.2

Courant Number mean: 2.28604e+20 max: 8.40228e+23 velocity magnitude: 3.89946e+22
PBiCG:  Solving for Ux, Initial residual = 0.999885, Final residual = 6.49499, No Iterations 1000
PBiCG:  Solving for Uy, Initial residual = 0.999815, Final residual = 3.9282, No Iterations 1000
PBiCG:  Solving for Uz, Initial residual = 0.999772, Final residual = 2.70425, No Iterations 1000
PCG:  Solving for p, Initial residual = 1, Final residual = 57.7895, No Iterations 1000
PCG:  Solving for p, Initial residual = 0.771788, Final residual = 124.919, No Iterations 1000
time step continuity errors : sum local = 4.00756e+33, global = 5.1915e+25, cumulative = 5.1915e+25
PCG:  Solving for p, Initial residual = 0.923169, Final residual = 4.28131, No Iterations 1000
PCG:  Solving for p, Initial residual = 0.74075, Final residual = 392.082, No Iterations 1000
time step continuity errors : sum local = 1.39632e+38, global = -1.04069e+30, cumulative = -1.04064e+30
ExecutionTime = 446.61 s  ClockTime = 447 s

Time = 0.22

Courant Number mean: 6.86548e+37 max: 1.692e+42 velocity magnitude: 6.1894e+40
PBiCG:  Solving for Ux, Initial residual = 0.999959, Final residual = 2.91466, No Iterations 1000
PBiCG:  Solving for Uy, Initial residual = 0.999976, Final residual = 0.549805, No Iterations 1000
PBiCG:  Solving for Uz, Initial residual = 0.99999, Final residual = 0.420483, No Iterations 1000
PCG:  Solving for p, Initial residual = 1, Final residual = 248.252, No Iterations 1000
PCG:  Solving for p, Initial residual = 0.0273632, Final residual = 0.0501284, No Iterations 1000
time step continuity errors : sum local = 1.22223e+60, global = 1.90958e+44, cumulative = 1.90958e+44
PCG:  Solving for p, Initial residual = 0.132324, Final residual = 1.12506, No Iterations 1000
PCG:  Solving for p, Initial residual = 0.0522075, Final residual = 0.24675, No Iterations 1000
time step continuity errors : sum local = 1.9022e+63, global = -1.83909e+50, cumulative = -1.83909e+50
ExecutionTime = 551.96 s  ClockTime = 552 s

Time = 0.24

Courant Number mean: 1.41686e+63 max: 2.14683e+67 velocity magnitude: 7.26454e+65
PBiCG:  Solving for Ux, Initial residual = 0.999941, Final residual = 5.11203, No Iterations 1000
PBiCG:  Solving for Uy, Initial residual = 0.99994, Final residual = 0.204469, No Iterations 1000
PBiCG:  Solving for Uz, Initial residual = 0.999928, Final residual = 1.03388, No Iterations 1000
PCG:  Solving for p, Initial residual = 1, Final residual = 3.266, No Iterations 1000
PCG:  Solving for p, Initial residual = 1.9343e-11, Final residual = 1.9343e-11, No Iterations 0
time step continuity errors : sum local = 1.47482e+88, global = -3.62724e+71, cumulative = -3.62724e+71
PCG:  Solving for p, Initial residual = 3.87133e-11, Final residual = 3.87133e-11, No Iterations 0
PCG:  Solving for p, Initial residual = 3.87133e-11, Final residual = 3.87133e-11, No Iterations 0
time step continuity errors : sum local = 2.95171e+88, global = -2.1468e+72, cumulative = -2.50952e+72
ExecutionTime = 633.62 s  ClockTime = 634 s

Time = 0.26

Courant Number mean: 8.67119e+87 max: 2.38864e+92 velocity magnitude: 8.00775e+90
PBiCG:  Solving for Ux, Initial residual = 0.999973, Final residual = 0.645976, No Iterations 1000
PBiCG:  Solving for Uy, Initial residual = 0.99999, Final residual = 0.272165, No Iterations 1000
PBiCG:  Solving for Uz, Initial residual = 0.999979, Final residual = 0.313018, No Iterations 1000
PCG:  Solving for p, Initial residual = 1, Final residual = 11.673, No Iterations 1000
PCG:  Solving for p, Initial residual = 2.40327e-11, Final residual = 2.40327e-11, No Iterations 0
time step continuity errors : sum local = 1.46936e+101, global = 1.28168e+98, cumulative = 1.28168e+98
PCG:  Solving for p, Initial residual = 7.36934e-11, Final residual = 7.36934e-11, No Iterations 0
PCG:  Solving for p, Initial residual = 7.36934e-11, Final residual = 7.36934e-11, No Iterations 0
time step continuity errors : sum local = 4.5056e+101, global = 1.7056e+98, cumulative = 2.98729e+98
ExecutionTime = 718.06 s  ClockTime = 718 s

Time = 0.28

Courant Number mean: 1.45564e+101 max: 9.1374e+104 velocity magnitude: 3.16353e+103
Floating point exception (core dumped)
cheers

Last edited by Artex85; January 3, 2012 at 09:56.
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Old   December 29, 2011, 20:57
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Tarak
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Hii,

Please check the quality of your mesh using the checkMesh utility, and judge whether the relevant parameters (e.g aspect ratio) look good or not.

Thanks,
Tarak
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Old   December 30, 2011, 04:35
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Vincent RIVOLA
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you can also run your computation by specifying a maximum courant number of 1 or 2, instead of specifying the time step.

This way, the time step will be adapted directly to avoid courant number being higher than the value you specify. At least, as long as possible.
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Old   December 30, 2011, 04:37
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Tarak
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You can also try the following link. It shows how to use an adjustable time step depending on the Courant No.
http://www.idurun.com/?p=371
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Old   December 30, 2011, 04:59
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Patrick Pazour
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Dear Foamers!

After the problems with the tet mesh, i designed a simple pipe with hexas to check the openfoam mesh files which are created out of pointwise. checkMesh is just Fine, courent number with icoFoam is ... yea going up. If i change the ncorrectors to zero the courant number is stable.
I tried to modify the icoFoam solver to be adjustable for the timesteps, dont get it worked.

Last edited by Artex85; January 3, 2012 at 09:26. Reason: Killed dead link
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Old   January 3, 2012, 04:26
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Could you check your link? I don't have access to the file
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Old   January 3, 2012, 04:36
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Hossein
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Hi
i write a loop in my UDF by C_FACE_loop. its worked in 3D but in 2D in fluent show this error "non-integer subscript expression: unsigned char"
whats that mean?
please help me to solve this
thanks
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Old   January 3, 2012, 09:06
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Patrick Pazour
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Dear Foamers!

The hex pipe is working, problem was the small cell size in combination with a too large timestep.

The tet pipe is still pending, I think there is a problem with the mesh.

The helix is done.

All downloadable here -->

Pipe meshes with pointwise
Working hex pipe
Crashing tet pipe
helix mesh with pointwise

Last edited by Artex85; January 5, 2012 at 04:52. Reason: update helix case
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Old   February 16, 2017, 04:44
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Hello dear users,

I'v got stock within the problem that the pressure solver diverges with the following error. This is naca airfoil low reynolds simulation using pimpleFoam. I would be eager if anybody can help me with this problem.
a timestep 1E-8 results in the same problem.

Bests,


Error:
------------------------------------------------
Courant Number mean: 5.23271e+031 max: 6.07791e+036
Time = 8e-008

PIMPLE: iteration 1
smoothSolver: Solving for Ux, Initial residual = nan, Final residual = nan, No Iterations 1000
smoothSolver: Solving for Uy, Initial residual = nan, Final residual = nan, No Iterations 1000
GAMG: Solving for p, Initial residual = nan, Final residual = nan, No Iterations 1000
GAMG: Solving for p, Initial residual = nan, Final residual = nan, No Iterations 1000


--> FOAM FATAL IO ERROR:
wrong token type - expected Scalar, found on line 0 the word 'nan'

file: C:/OpenFOAM/16.10/ACER-3.0.x/run/NACA2415-fine-grid/system/data.solverPerformance.p at line 0.

From function operator>>(Istream&, Scalar&)
in file lnInclude/Scalar.C at line 93.

FOAM exiting




Mesh:
-------------------------------------------------------------------
Mesh stats
points: 69172
internal points: 0
faces: 136901
internal faces: 67729
cells: 34105
faces per cell: 6
boundary patches: 4
point zones: 0
face zones: 0
cell zones: 0

Overall number of cells of each type:
hexahedra: 34105
prisms: 0
wedges: 0
pyramids: 0
tet wedges: 0
tetrahedra: 0
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
VELOCITY_INLET 433 868 ok (non-closed singly connected)
PRESSURE_FARFIELD 195 392 ok (non-closed singly connected)
AIRFOIL_WALL 334 668 ok (non-closed singly connected)
frontAndBackPlanes 68210 69172 ok (non-closed singly connected)

Checking geometry...
Overall domain bounding box (-1.39977 -1.5 -0.046096) (2.1 1.5 0.046096)
Mesh has 2 geometric (non-empty/wedge) directions (1 1 0)
Mesh has 2 solution (non-empty) directions (1 1 0)
All edges aligned with or perpendicular to non-empty directions.
Boundary openness (-3.35274e-017 2.62186e-018 -1.42503e-019) OK.
Max cell openness = 1.59929e-013 OK.
Max aspect ratio = 218.673 OK.
Minimum face area = 5.05592e-011. Maximum face area = 0.0183235. Face area magnitudes OK.
Min volume = 4.66115e-012. Max volume = 0.0014232. Total volume = 0.878736. Cell volumes OK.
Mesh non-orthogonality Max: 89.8884 average: 11.482
*Number of severely non-orthogonal (> 70 degrees) faces: 423.
Non-orthogonality check OK.
<<Writing 423 non-orthogonal faces to set nonOrthoFaces
Face pyramids OK.
Max skewness = 0.637561 OK.
Coupled point location match (average 0) OK.

Mesh OK.
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Old   February 16, 2017, 14:40
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Uwe Pilz
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Dear arzi,

n pimple it is possible to set adjustTimeStep to yes and give the maximal Courant number. This ist the best way to work with pimple.

controlDict:
Code:
adjustTimeStep  yes;

maxCo           1;
Please keep in mind: A fine graded mesh needs a small time step for keeping the Courant number low. A high turbulent flow requires to set Co lower than 1, even fro pimple (which usual accepts Co of around 5).
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