[Jackie Chen]

Hi

I try to simulate the flow around tidal turbines by using pimpleDyMFoam. however, the simulation stopped right after i executing the "Allrun" command. The msg in the log file are shown as below, anyone know the reason?

Thanks

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

Create mesh for time = 0

Selecting dynamicFvMesh solidBodyMotionFvMesh
Selecting solid-body motion function rotatingMotion
Applying solid body motion to cellZone innercylinder
Reading field p

Reading field U

Reading/calculating face flux field phi

AMI: Creating addressing and weights between 2660 source faces and 2660 target faces
AMI: Patch source weights min/max/average = 4.83927e-09, 1.00063, 0.834913
AMI: Patch target weights min/max/average = 0, 1.20756, 0.834843
Selecting incompressible transport model Newtonian
Selecting turbulence model type RASModel
Selecting RAS turbulence model kEpsilon
kEpsilonCoeffs
{
Cmu 0.09;
C1 1.44;
C2 1.92;
sigmaEps 1.3;
}

Reading field rAU if present

No field sources present


PIMPLE: no residual control data found. Calculations will employ 3 corrector loops


Starting time loop

Courant Number mean: 9.59912e-05 max: 0.0060191
deltaT = 1.1999e-05
Time = 1.1999e-05

solidBodyMotionFunctions::rotatingMotion::transfor mation(): Time = 1.1999e-05 transformation: ((0 0 0) (1 (0 -5.02615e-05 0)))
AMI: Creating addressing and weights between 2660 source faces and 2660 target faces
AMI: Patch source weights min/max/average = 1.91434e-05, 1.21386, 0.961821
AMI: Patch target weights min/max/average = 0, 1.24578, 0.960982
PIMPLE: iteration 1
[1] #0 Foam::error:rintStack(Foam::Ostream&) in "/opt/openfoam211/platforms/linux64GccDPOpt/lib/libOpenFOAM.so"
[1] #1 Foam::sigFpe::sigHandler(int) in "/opt/openfoam211/platforms/linux64GccDPOpt/lib/libOpenFOAM.so"
[1] #2 in "/lib/x86_64-linux-gnu/libc.so.6"
[1] #3 Foam::divide(Foam::Field<double>&, double const&, Foam::UList<double> const&) in "/opt/openfoam211/platforms/linux64GccDPOpt/lib/libOpenFOAM.so"
[1] #4 Foam::tmp<Foam::GeometricField<double, Foam::fvPatchField, Foam::volMesh> > Foam:perator/<Foam::fvPatchField, Foam::volMesh>(Foam::dimensioned<double> const&, Foam::tmp<Foam::GeometricField<double, Foam::fvPatchField, Foam::volMesh> > const&) in "/opt/openfoam211/platforms/linux64GccDPOpt/bin/pimpleDyMFoam"
[1] #5
[1] in "/opt/openfoam211/platforms/linux64GccDPOpt/bin/pimpleDyMFoam"
[1] #6 __libc_start_main in "/lib/x86_64-linux-gnu/libc.so.6"
[1] #7
[1] in "/opt/openfoam211/platforms/linux64GccDPOpt/bin/pimpleDyMFoam"
[ubuntu:05018] *** Process received signal ***
[ubuntu:05018] Signal: Floating point exception (8)
[ubuntu:05018] Signal code: (-6)
[ubuntu:05018] Failing at address: 0x3e80000139a
[ubuntu:05018] [ 0] /lib/x86_64-linux-gnu/libc.so.6(+0x364a0) [0x7f15e79524a0]
[ubuntu:05018] [ 1] /lib/x86_64-linux-gnu/libc.so.6(gsignal+0x35) [0x7f15e7952425]
[ubuntu:05018] [ 2] /lib/x86_64-linux-gnu/libc.so.6(+0x364a0) [0x7f15e79524a0]
[ubuntu:05018] [ 3] /opt/openfoam211/platforms/linux64GccDPOpt/lib/libOpenFOAM.so(_ZN4Foam6divideERNS_5FieldIdEERKdRK NS_5UListIdEE+0x24) [0x7f15e8aa2754]
[ubuntu:05018] [ 4] pimpleDyMFoam(_ZN4FoamdvINS_12fvPatchFieldENS_7vol MeshEEENS_3tmpINS_14GeometricFieldIdT_T0_EEEERKNS_ 11dimensionedIdEERKS8_+0x2a0) [0x43e180]
[ubuntu:05018] [ 5] pimpleDyMFoam() [0x4186cb]
[ubuntu:05018] [ 6] /lib/x86_64-linux-gnu/libc.so.6(__libc_start_main+0xed) [0x7f15e793d76d]
[ubuntu:05018] [ 7] pimpleDyMFoam() [0x41c38d]
[ubuntu:05018] *** End of error message ***

[andre.weiner]

The solver crashes because some weights are zero.

AMI: Patch source weights min/max/average = 1.91434e-05, 1.21386, 0.961821
AMI: Patch target weights min/max/average = 0, 1.24578, 0.960982

You can try the low weight correction available in OF 2.3

AMIPatch 
{ 
    type            cyclicAMI; 
    ... 
    lowWeightCorrection 0.2; 
}

Also your mesh seems to be poor at the AMI-patches (average should be close to one)
so maybe you should improve the mesh quality first.

Best regards!

[Jackie Chen]

Andre

Thanks a lot. Normally how you improve the quality of mesh?

[andre.weiner]

A better mesh quality regarding to AMI faces in OF you achieve e.g. with :

- a better approximation of your geometry
- AMI cell faces of the same shape and size

How you accomplish this depends on your meshing tool.

[Jackie Chen]

Andre

what meshing tool are you using?

Best regards

[andre.weiner]

That pretty much depends on the available resources :-)
You can use snappyHexMesh like in the propeller tutorial

cd $FOAM_TUTORIALS/incompressible/pimpleDyMFoam/propeller/

[Jackie Chen]

Andre

My case is based on thsi tutorial.　M using snappyhexmesh utility, but i only simple execute the command dunno how to set the details to control the quality of the mesh.
May be i need to understand the snappyhexMeshDict so that i can produce more quality mesh of my turbine.