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Old   April 30, 2013, 10:48
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  #381
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Quote:
Hi Kilroy,

You do not want to run your simulations as root. It is simply too dangerous in terms of you ending up deleting files of vital importance or similar scary things.

Instead: Compile waveDyMFoam, when you are logged in as your own user. This should be done by placing all of waves2Foam in your own directory rather than /opt/<ETC>/waves2Foam

Kind regards

Niels
Niels, thank you very much for your time and help. From now on I will compile as you recommended.

I am still learning how to use Linux and this case is a very good experience for me to how to work with the environment.
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Old   May 1, 2013, 03:27
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Hi Niels.

I am working with wave impacts on a monopile (cylinder) with waves on the limit of breaking.
Attached is a plot of the force/moment and I would like to hear if you or others have seen something similar?
The two first waveimpcats at 35 and 45 sec is breaking while the three last impacts seam to decrease in energy and become more and more smooth(no breaking on the last impact).

Since the force/moment is twice the size for the 3rd wave impact compared to the last I wonder which impact is realistic. Could there be unnatural interference from the first breaking waves reflecting on the relaxation zones making the 3rd wave peak higher than it should?


I hope you or others can give some feedback.
Attached Images
File Type: png force.png (39.6 KB, 25 views)
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Old   May 2, 2013, 03:36
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Niels Gjoel Jacobsen
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Hi Jonas,

If the waves are breaking at different locations, then it does make sense. You could for instance log the surface elevation at different locations down the flume.

I would, however, recommend that you perform an validation exercise, where you compare the results with laboratory experiments.

Kind regards

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Old   May 2, 2013, 09:50
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Niels,

I am having problems with my "waveDyMFoam" which I modified from "interDyMFoam". I am trying to run a simple 2D case where a box is floating on the water under the effect of waves. The video of the case can be seen here:

https://www.youtube.com/watch?featur...&v=YKbj_7JMRl8

Also the case can be downloaded from here:

https://sites.google.com/site/jordim...edirects=0&d=1

At first the case was not running because of some missing schemes in the "fvSchemes" file. So, I added the following lines under "divSchemes" section:

div((muEff*dev(T(grad(U))))) Gauss linear;
div((nuEff*dev(T(grad(U))))) Gauss linear;

When I try to run the case, I get the following errors:

Quote:
sixDoFRigidBodyMotion constraints converged in 1 iterations
Constraint force: (0 0 0)
Constraint moment: (0 0 0)
Centre of mass: (10.3657 0.00896592 0.05)
Linear velocity: (0.169457 0.0262615 3.6077e-17)
Angular velocity: (-3.19807e-28 -1.37522e-26 -5.1003e-12)
GAMG: Solving for cellDisplacementx, Initial residual = 0.000224045, Final residual = 8.12868e-06, No Iterations 2
GAMG: Solving for cellDisplacementy, Initial residual = 0.000224045, Final residual = 8.12868e-06, No Iterations 2
Execution time for mesh.update() = 0.23 s
time step continuity errors : sum local = 5.05277e-05, global = -3.01844e-19, cumulative = -5.40294e-08
GAMG: Solving for pcorr, Initial residual = 1, Final residual = 8.97864e-08, No Iterations 17
GAMG: Solving for pcorr, Initial residual = 0.250457, Final residual = 5.28244e-08, No Iterations 15
time step continuity errors : sum local = 8.53279e-05, global = -1.02447e-11, cumulative = -5.40397e-08
MULES: Solving for alpha1
Phase-1 volume fraction = 0.666764 Min(alpha1) = -1.93586e-23 Max(alpha1) = 1
DILUPBiCG: Solving for Ux, Initial residual = 0.0130186, Final residual = 1.17418e-10, No Iterations 1
DILUPBiCG: Solving for Uy, Initial residual = 0.0946691, Final residual = 7.58036e-11, No Iterations 1
GAMG: Solving for p_rgh, Initial residual = 0.261841, Final residual = 5.56369e-08, No Iterations 12
GAMG: Solving for p_rgh, Initial residual = 0.000997295, Final residual = 4.38728e-08, No Iterations 7
time step continuity errors : sum local = 7.35319e-21, global = -4.08938e-21, cumulative = -5.40397e-08
GAMG: Solving for p_rgh, Initial residual = 0.000600283, Final residual = 5.20561e-08, No Iterations 6
GAMG: Solving for p_rgh, Initial residual = 0.00035003, Final residual = 4.53092e-08, No Iterations 5
time step continuity errors : sum local = 7.67551e-21, global = 6.55771e-21, cumulative = -5.40397e-08
GAMG: Solving for p_rgh, Initial residual = 0.000171914, Final residual = 7.8525e-08, No Iterations 4
GAMG: Solving for p_rgh, Initial residual = 5.06367e-05, Final residual = 6.19844e-09, No Iterations 6
time step continuity errors : sum local = 1.04979e-21, global = 1.00984e-21, cumulative = -5.40397e-08
ExecutionTime = 47953.3 s ClockTime = 48046 s

Interface Courant Number mean: 2.38452e-06 max: 0.00400263
Courant Number mean: 0.000200405 max: 0.425284
deltaT = 2.62873e-13
--> FOAM Warning :
From function Time:perator++()
in file db/Time/Time.C at line 1029
Increased the timePrecision from 14 to 16 to distinguish between timeNames at time 12.8093
Time = 12.80933457039102

sixDoFRigidBodyMotion constraints converged in 1 iterations
Constraint force: (0 0 0)
Constraint moment: (0 0 0)
Centre of mass: (10.3657 0.00896592 0.05)
Linear velocity: (0.169262 0.026284 3.60775e-17)
Angular velocity: (-3.19814e-28 -1.37523e-26 -5.10294e-12)
GAMG: Solving for cellDisplacementx, Initial residual = 0.000221903, Final residual = 8.00376e-06, No Iterations 2
GAMG: Solving for cellDisplacementy, Initial residual = 0.000221903, Final residual = 8.00376e-06, No Iterations 2
Execution time for mesh.update() = 0.23 s
time step continuity errors : sum local = 5.01594e-05, global = -1.26375e-19, cumulative = -5.40397e-08
GAMG: Solving for pcorr, Initial residual = 1, Final residual = 8.65576e-08, No Iterations 18
GAMG: Solving for pcorr, Initial residual = 0.181331, Final residual = 5.39143e-08, No Iterations 15
time step continuity errors : sum local = 7.78955e-05, global = -1.19518e-11, cumulative = -5.40516e-08
MULES: Solving for alpha1
Phase-1 volume fraction = 0.666764 Min(alpha1) = -1.88721e-23 Max(alpha1) = 1
DILUPBiCG: Solving for Ux, Initial residual = 0.0129951, Final residual = 6.3627e-11, No Iterations 1
DILUPBiCG: Solving for Uy, Initial residual = 0.0946374, Final residual = 9.16735e-11, No Iterations 1
GAMG: Solving for p_rgh, Initial residual = 0.205321, Final residual = 7.70156e-08, No Iterations 11
GAMG: Solving for p_rgh, Initial residual = 0.000734827, Final residual = 3.76525e-08, No Iterations 7
time step continuity errors : sum local = 3.98678e-21, global = -2.59775e-22, cumulative = -5.40516e-08
GAMG: Solving for p_rgh, Initial residual = 0.00041682, Final residual = 7.59192e-08, No Iterations 5
GAMG: Solving for p_rgh, Initial residual = 0.000186038, Final residual = 4.30575e-08, No Iterations 5
time step continuity errors : sum local = 4.24988e-21, global = -3.26612e-21, cumulative = -5.40516e-08
GAMG: Solving for p_rgh, Initial residual = 0.000101912, Final residual = 4.99173e-08, No Iterations 5
GAMG: Solving for p_rgh, Initial residual = 3.9727e-05, Final residual = 8.3358e-09, No Iterations 6
time step continuity errors : sum local = 8.22266e-22, global = -6.35014e-22, cumulative = -5.40516e-08
ExecutionTime = 47954.4 s ClockTime = 48047 s

Interface Courant Number mean: 2.30322e-06 max: 0.0032262
Courant Number mean: 0.000207624 max: 0.544706
deltaT = 1.20649e-13
Time = 12.80933457039114

sixDoFRigidBodyMotion constraints converged in 1 iterations
Constraint force: (0 0 0)
Constraint moment: (0 0 0)
Centre of mass: (10.3657 0.00896592 0.05)
Linear velocity: (0.169412 0.0262994 3.60779e-17)
Angular velocity: (-3.19822e-28 -1.37522e-26 -5.10071e-12)
GAMG: Solving for cellDisplacementx, Initial residual = 0.00021926, Final residual = 7.84774e-06, No Iterations 2
GAMG: Solving for cellDisplacementy, Initial residual = 0.00021926, Final residual = 7.84774e-06, No Iterations 2
Execution time for mesh.update() = 0.23 s
time step continuity errors : sum local = 3.57512e-05, global = 7.09289e-19, cumulative = -5.40516e-08
GAMG: Solving for pcorr, Initial residual = 1, Final residual = 7.51115e-08, No Iterations 20
GAMG: Solving for pcorr, Initial residual = 0.121942, Final residual = 9.90107e-08, No Iterations 14
time step continuity errors : sum local = 8.06169e-05, global = -3.4904e-11, cumulative = -5.40865e-08
#0 Foam::error:rintStack(Foam::Ostream&) in "/opt/openfoam220/platforms/linux64GccDPOpt/lib/libOpenFOAM.so"
#1 Foam::sigFpe::sigHandler(int) in "/opt/openfoam220/platforms/linux64GccDPOpt/lib/libOpenFOAM.so"
#2 in "/lib/x86_64-linux-gnu/libc.so.6"
#3 void Foam::MULES::limiter<Foam::geometricOneField, Foam::zeroField, Foam::zeroField>(Foam::Field<double>&, Foam::geometricOneField const&, Foam::GeometricField<double, Foam::fvPatchField, Foam::volMesh> const&, Foam::GeometricField<double, Foam::fvsPatchField, Foam::surfaceMesh> const&, Foam::GeometricField<double, Foam::fvsPatchField, Foam::surfaceMesh> const&, Foam::zeroField const&, Foam::zeroField const&, double, double, int) in "/opt/openfoam220/platforms/linux64GccDPOpt/lib/libfiniteVolume.so"
#4 void Foam::MULES::limit<Foam::geometricOneField, Foam::zeroField, Foam::zeroField>(Foam::geometricOneField const&, Foam::GeometricField<double, Foam::fvPatchField, Foam::volMesh> const&, Foam::GeometricField<double, Foam::fvsPatchField, Foam::surfaceMesh> const&, Foam::GeometricField<double, Foam::fvsPatchField, Foam::surfaceMesh>&, Foam::zeroField const&, Foam::zeroField const&, double, double, int, bool) in "/opt/openfoam220/platforms/linux64GccDPOpt/lib/libfiniteVolume.so"
#5 Foam::MULES::explicitSolve(Foam::GeometricField<do uble, Foam::fvPatchField, Foam::volMesh>&, Foam::GeometricField<double, Foam::fvsPatchField, Foam::surfaceMesh> const&, Foam::GeometricField<double, Foam::fvsPatchField, Foam::surfaceMesh>&, double, double) in "/opt/openfoam220/platforms/linux64GccDPOpt/lib/libfiniteVolume.so"
#6
in "/home/meta/OpenFOAM/root-2.2.0/platforms/linux64GccDPOpt/bin/waveDyMFoam"
#7 __libc_start_main in "/lib/x86_64-linux-gnu/libc.so.6"
#8
in "/home/meta/OpenFOAM/root-2.2.0/platforms/linux64GccDPOpt/bin/waveDyMFoam"
Floating point exception (core dumped)
And my analysis crashes around the 12th second. I checked my mesh and everything seemed ok to me.

Do you have any idea what may be the cause of that problem?

Thank you very much for your time and help.

Kilroy
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Old   May 3, 2013, 07:38
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  #385
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Niels Gjoel Jacobsen
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Hi Kilroy,

The simulation has "crashed" way before the part of the log file, which you have shown, so it is not possible to say anything.

Have you tried the following:

1. Running the moving mesh simulation without waves to see, if the crash is related to waves or mesh motion?

2. Running the simulation without a moving mesh. In the case of the latter, merely state the following in your constant/dynamicMeshDict

Code:
dynamicFvMesh staticFvMesh;
which removes all the mesh motion from your simulation even though you are running with your waveDyMFoam solver.

Kind regards

Niels
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Old   May 3, 2013, 16:17
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Niels,

Thank you so much. I will try those steps and let you know.

Kilroy
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Old   May 3, 2013, 17:19
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Niels,

I think I pin-point the problem. It is not because of the waves, it is because of the moving mesh.

My original "dynamicMeshDict" file looks like below:

Quote:
dynamicFvMesh dynamicMotionSolverFvMesh;

motionSolverLibs ("libfvMotionSolvers.so");

solver displacementLaplacian;

diffusivity inverseDistance (floatingObject);

displacementLaplacianCoeffs
{
diffusivity inverseDistance (floatingObject);
}
Do you think playing with the value of "dynamicFvMesh" will work?

Can you please give me some suggestions?

Thank you very much for your help and time.

Kilroy
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Old   May 4, 2013, 07:34
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Hi Dear Foamers

i am working on periodicsolitary tutorial and i convert a mesh file from gammbit to openfoam and i run the case in setwaveField i have no problem but when i run the waveFoam i have this error as follows:


Selecting incompressible transport model Newtonian
Selecting incompressible transport model Newtonian
Selecting turbulence model type laminar
Calculating field g.h

time step continuity errors : sum local = 9.93914e-11, global = -2.72782e-19, cumulative = -2.72782e-19
#0 Foam::error:rintStack(Foam::Ostream&) in "/opt/openfoam211/platforms/linux64GccDPOpt/lib/libOpenFOAM.so"
#1 Foam::sigFpe::sigHandler(int) in "/opt/openfoam211/platforms/linux64GccDPOpt/lib/libOpenFOAM.so"
#2 in "/lib/x86_64-linux-gnu/libc.so.6"
#3 Foam::GAMGSolver::scalingFactor(Foam::Field<double >&, Foam::Field<double> const&, Foam::Field<double> const&, Foam::Field<double> const&) const in "/opt/openfoam211/platforms/linux64GccDPOpt/lib/libOpenFOAM.so"
#4 Foam::GAMGSolver::scalingFactor(Foam::Field<double >&, Foam::lduMatrix const&, Foam::Field<double>&, Foam::FieldField<Foam::Field, double> const&, Foam::UPtrList<Foam::lduInterfaceField const> const&, Foam::Field<double> const&, unsigned char) const in "/opt/openfoam211/platforms/linux64GccDPOpt/lib/libOpenFOAM.so"
#5 Foam::GAMGSolver::Vcycle(Foam::PtrList<Foam::lduMa trix::smoother> const&, Foam::Field<double>&, Foam::Field<double> const&, Foam::Field<double>&, Foam::Field<double>&, Foam::Field<double>&, Foam::PtrList<Foam::Field<double> >&, Foam::PtrList<Foam::Field<double> >&, unsigned char) const in "/opt/openfoam211/platforms/linux64GccDPOpt/lib/libOpenFOAM.so"
#6 Foam::GAMGSolver::solve(Foam::Field<double>&, Foam::Field<double> const&, unsigned char) const in "/opt/openfoam211/platforms/linux64GccDPOpt/lib/libOpenFOAM.so"
#7 Foam::fvMatrix<double>::solve(Foam::dictionary const&) in "/opt/openfoam211/platforms/linux64GccDPOpt/lib/libfiniteVolume.so"
#8 Foam::fvMatrix<double>::solve() in "/home/openfoam/OpenFOAM/openfoam-2.1.1/platforms/linux64GccDPOpt/bin/waveFoam"
#9
in "/home/openfoam/OpenFOAM/openfoam-2.1.1/platforms/linux64GccDPOpt/bin/waveFoam"
#10 __libc_start_main in "/lib/x86_64-linux-gnu/libc.so.6"
#11
in "/home/openfoam/OpenFOAM/openfoam-2.1.1/platforms/linux64GccDPOpt/bin/waveFoam"
Floating point exception (core dumped)


any foamer can help me?

tnx alot
kings regards for all
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Old   May 6, 2013, 14:15
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Quote:
Originally Posted by ngj View Post
Hi Jason,

You have to be more specific on your concerns, since it is important for you to tell, how your results differs from the experimental data, otherwise it is hard to tell, where the problems could be. Also, a snap-shot of the mesh with grid lines are more instructive, since you have seen from the article that it is of great importance to retain an aspect ratio of 1 (one).

Secondly, with respect to my differences in the domain, then it is only the truncation at the "shoreline", which differs from the experimental set-up.

Kind regards,

Niels


Hi Niels,

I'm still struggling with the spilling breaker case. I created a new mesh by snappyHexMesh, aspect ratios around unity this time. As seen in the two screenshots for mesh around inlet and outlet, I refined the mesh at the sloped beach and around the still water surface. checkMesh reports ok.

https://www.dropbox.com/s/8r6gg5uihf...sh%20inlet.png
https://www.dropbox.com/s/utn2v2mxud...h%20outlet.png

But when I run the case, it terminated after some time. It seems to be connected with the GAMGsolve for p_rgh. If I change the mesh density it rans a little bit longer, still terminated after some time.

Have you ever experienced this kind of problem? Is this the reason you altered slightly the domain setup? Or there is some problem with my mesh.

Here is the log for waveFoam.

MULES: Solving for alpha1
Liquid phase volume fraction = 0.448276 Min(alpha1) = -0.0150611 Max(alpha1) = 1
DILUPBiCG: Solving for Ux, Initial residual = 0.0025231, Final residual = 3.68185e-13, No Iterations 3
DILUPBiCG: Solving for Uy, Initial residual = 0.00352815, Final residual = 1.05959e-12, No Iterations 3
GAMG: Solving for p_rgh, Initial residual = 0.00669198, Final residual = 9.62446e+85, No Iterations 1000
[0] #0 Foam::error:rintStack(Foam::Ostream&) in "/opt/openfoam211/platforms/linux64GccDPOpt/lib/libOpenFOAM.so"
[0] #1 Foam::sigFpe::sigHandler(int) in "/opt/openfoam211/platforms/linux64GccDPOpt/lib/libOpenFOAM.so"
[0] #2 in "/lib/x86_64-linux-gnu/libc.so.6"
[0] #3 Foam::GAMGSolver::scalingFactor(Foam::Field<double >&, Foam::Field<double> const&, Foam::Field<double> const&, Foam::Field<double> const&) const in "/opt/openfoam211/platforms/linux64GccDPOpt/lib/libOpenFOAM.so"
[0] #4 Foam::GAMGSolver::scalingFactor(Foam::Field<double >&, Foam::lduMatrix const&, Foam::Field<double>&, Foam::FieldField<Foam::Field, double> const&, Foam::UPtrList<Foam::lduInterfaceField const> const&, Foam::Field<double> const&, unsigned char) const in "/opt/openfoam211/platforms/linux64GccDPOpt/lib/libOpenFOAM.so"
[0] #5 Foam::GAMGSolver::Vcycle(Foam::PtrList<Foam::lduMa trix::smoother> const&, Foam::Field<double>&, Foam::Field<double> const&, Foam::Field<double>&, Foam::Field<double>&, Foam::Field<double>&, Foam::PtrList<Foam::Field<double> >&, Foam::PtrList<Foam::Field<double> >&, unsigned char) const in "/opt/openfoam211/platforms/linux64GccDPOpt/lib/libOpenFOAM.so"
[0] #6 Foam::GAMGSolver::solve(Foam::Field<double>&, Foam::Field<double> const&, unsigned char) const in "/opt/openfoam211/platforms/linux64GccDPOpt/lib/libOpenFOAM.so"
[0] #7 Foam::fvMatrix<double>::solve(Foam::dictionary const&) in "/opt/openfoam211/platforms/linux64GccDPOpt/lib/libfiniteVolume.so"
[0] #8
[0] in "/home/qingping/OpenFOAM/qingping-2.1.1/platforms/linux64GccDPOpt/bin/waveFoam"
[0] #9 __libc_start_main in "/lib/x86_64-linux-gnu/libc.so.6"
[0] #10
[0] in "/home/qingping/OpenFOAM/qingping-2.1.1/platforms/linux64GccDPOpt/bin/waveFoam"

================================================== =============
Here is for another mesh, coarser

MULES: Solving for alpha1
Liquid phase volume fraction = 0.453635 Min(alpha1) = -0.00643746 Max(alpha1) = 1
DILUPBiCG: Solving for Ux, Initial residual = 0.00202468, Final residual = 2.13295e-11, No Iterations 4
DILUPBiCG: Solving for Uy, Initial residual = 0.00375042, Final residual = 6.097e-10, No Iterations 3
[0] #0 Foam::error:rintStack(Foam::Ostream&) in "/opt/openfoam211/platforms/linux64GccDPOpt/lib/libOpenFOAM.so"
[0] #1 Foam::sigFpe::sigHandler(int) in "/opt/openfoam211/platforms/linux64GccDPOpt/lib/libOpenFOAM.so"
[0] #2 in "/lib/x86_64-linux-gnu/libc.so.6"
[0] #3 Foam::GAMGSolver::scalingFactor(Foam::Field<double >&, Foam::Field<double> const&, Foam::Field<double> const&, Foam::Field<double> const&) const in "/opt/openfoam211/platforms/linux64GccDPOpt/lib/libOpenFOAM.so"
[0] #4 Foam::GAMGSolver::scalingFactor(Foam::Field<double >&, Foam::lduMatrix const&, Foam::Field<double>&, Foam::FieldField<Foam::Field, double> const&, Foam::UPtrList<Foam::lduInterfaceField const> const&, Foam::Field<double> const&, unsigned char) const in "/opt/openfoam211/platforms/linux64GccDPOpt/lib/libOpenFOAM.so"
[0] #5 Foam::GAMGSolver::Vcycle(Foam::PtrList<Foam::lduMa trix::smoother> const&, Foam::Field<double>&, Foam::Field<double> const&, Foam::Field<double>&, Foam::Field<double>&, Foam::Field<double>&, Foam::PtrList<Foam::Field<double> >&, Foam::PtrList<Foam::Field<double> >&, unsigned char) const in "/opt/openfoam211/platforms/linux64GccDPOpt/lib/libOpenFOAM.so"
[0] #6 Foam::GAMGSolver::solve(Foam::Field<double>&, Foam::Field<double> const&, unsigned char) const in "/opt/openfoam211/platforms/linux64GccDPOpt/lib/libOpenFOAM.so"
[0] #7 Foam::fvMatrix<double>::solve(Foam::dictionary const&) in "/opt/openfoam211/platforms/linux64GccDPOpt/lib/libfiniteVolume.so"
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Old   May 6, 2013, 14:22
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Options in fvSolution: (i didn't change anything)
p_rgh GAMG
{
tolerance 1e-7;
relTol 0.0;
smoother DIC;//GaussSeidel;
nPreSweeps 0;
nPostSweeps 2;
nFinestSweeps 2;
cacheAgglomeration true;
nCellsInCoarsestLevel 10;
agglomerator faceAreaPair;
mergeLevels 1;
};

PIMPLE
{
pdRefCell 0;
pdRefValue 0;
momentumPredictor yes;
nOuterCorrectors 1;
nCorrectors 3;
nNonOrthogonalCorrectors 2;
nAlphaCorr 1;
nAlphaSubCycles 1;
cAlpha 1;
}
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Old   May 7, 2013, 03:47
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  #391
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@Mohamad: It crashes immediately, while initialising the pressure, so I would assume that you have problems with your boundary and/or initial conditions.
The simulation crashes with a "GAMG::scalingFactor" problem. I have never figured out what this really means, however, it seems to be linked to negative void fractions.
Have you tried to see, whether something is wrong with the mesh? Here I would recommend that you test with a stagnant body of water.

@Jason: Please see above with the GAMG::scalingFactor. You are probably experiencing the crash due to negative void fractions.
Yes, I truncated the upper part to avoid instabilities between air/water/bed.

Kind regards

Niels
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Old   May 8, 2013, 06:07
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@Niles and @Jasak
Hello
How are you !!


i had some problem with wave 2foam periodic solitary
at first i meshing my model in gambit and then convert it to foam
and opean foam didnot have any problem with it
after change boundry conditions and setwaveField
when i run wavefoam for solve problem it have this error
plz help me

thank a lot
albert

/*---------------------------------------------------------------------------*\
| ========= | |
| \\ / F ield | OpenFOAM: The Open Source CFD Toolbox |
| \\ / O peration | Version: 2.1.1 |
| \\ / A nd | Web: www.OpenFOAM.org |
| \\/ M anipulation | |
\*---------------------------------------------------------------------------*/
Build : 2.1.1-221db2718bbb
Exec : waveFoam
Date : May 08 2013
Time : 14:27:52
Host : "albert-VPCF23EFX"
PID : 2513
Case : /home/albert/Desktop/periodicSolitary
nProcs : 1
fileModificationChecking : Monitoring run-time modified files using timeStampMaster
allowSystemOperations : Disallowing user-supplied system call operations

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

Create mesh for time = 0

// using new solver syntax:
pcorr
{
solver GAMG;
tolerance 1e-07;
relTol 0;
smoother DIC;
nPreSweeps 0;
nPostSweeps 2;
nFinestSweeps 2;
cacheAgglomeration true;
nCellsInCoarsestLevel 10;
agglomerator faceAreaPair;
mergeLevels 1;
}

// using new solver syntax:
p_rgh
{
solver GAMG;
tolerance 1e-07;
relTol 0;
smoother DIC;
nPreSweeps 0;
nPostSweeps 2;
nFinestSweeps 2;
cacheAgglomeration true;
nCellsInCoarsestLevel 10;
agglomerator faceAreaPair;
mergeLevels 1;
}

// using new solver syntax:
p_rghFinal
{
solver GAMG;
tolerance 1e-08;
relTol 0;
smoother DIC;
nPreSweeps 0;
nPostSweeps 2;
nFinestSweeps 2;
cacheAgglomeration true;
nCellsInCoarsestLevel 10;
agglomerator faceAreaPair;
mergeLevels 1;
}

// using new solver syntax:
U
{
solver PBiCG;
preconditioner DILU;
tolerance 1e-09;
relTol 0;
}

// using new solver syntax:
UFinal
{
solver PBiCG;
preconditioner DILU;
tolerance 1e-09;
relTol 0;
}

// using new solver syntax:
gamma
{
solver PBiCG;
preconditioner DILU;
tolerance 1e-07;
relTol 0;
}


PIMPLE: Operating solver in PISO mode


Reading g

Reading waveProperties
Reading field p_rgh

Reading field alpha1

Reading field U

Reading/calculating face flux field phi

Reading transportProperties

Selecting incompressible transport model Newtonian
Selecting incompressible transport model Newtonian
Selecting turbulence model type laminar
Calculating field g.h

time step continuity errors : sum local = 6.53598e-16, global = 1.97658e-17, cumulative = 1.97658e-17
GAMG: Solving for pcorr, Initial residual = 0.903804, Final residual = nan, No Iterations 1000
GAMG: Solving for pcorr, Initial residual = nan, Final residual = nan, No Iterations 1000


--> FOAM FATAL IO ERROR:
wrong token type - expected Scalar, found on line 3 the word 'nan'

file: /home/mohammadreza/Desktop/periodicSolitary/system/data::solverPerformance:corr at line 3.

From function operator>>(Istream&, Scalar&)
in file lnInclude/Scalar.C at line 91.

FOAM exiting
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Old   May 9, 2013, 09:16
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Hi Albert,

I have never seen NaN in OpenFoam before, so I have no clue on how to proceed.
Can you solve simple, incompressible, steady state flows in your domain? I heavily suspect the mesh to be corrupted in one way or the other. You are actually the second guy in this thread within a week having problems with meshes imported from Gambit.

Kind regards

Niels
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Old   May 16, 2013, 13:11
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Niels,

I am working on to modify the standard "wigley hull" tutorial that comes with OpenFOAM in such a way that the hull will be under the effect of waves. I have successfully managed to do that when the speed of the water and the wave directions are the same and I am getting very good results.

But now I want to define the speed of the water in x-direction and the wave direction making 45 degrees with the x-axis. I am trying to simulate the condition when the ship is traveling with a constant speed (speed of the water) and cutting the waves with 45 degrees.

Can I accomplish that by using "waves2Foam" toolbox?
And what would be the best modeling strategy (changing the shape of the computational domain and adding new patches, etc.)?

Can you please give me some suggestions?

Thanks,
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Old   May 16, 2013, 13:39
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Hi Niles
thank you so mush i try it with other meshing software

mr-albert
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Old   May 17, 2013, 04:03
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Hi Kilroy,

I have never thought about such a setup, and I do not know how you should go about it.

It is nice that you get good results with co-directional waves, so please share your experiences here with the more complex setup.

Kind regards

Niels

Edit 2013.05.17, 12:15: Of course you have to carefully choose the correct current, which gives you a steady ship in the computational domain. The waves will then have to be super-imposed on these waves. Neglecting the sideways drift of the ship due to the current, this current field should be fairly easy to "derive".

Last edited by ngj; May 17, 2013 at 06:03.
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Old   May 17, 2013, 17:36
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Niels,

I thought that maybe I can simulate the movement of the hull by moving its mesh. So, I decided to look into the movingCone tutorial.

I have just gone through it and I can see that, as the object moves to the right side, mesh on the right side is contracting and the mesh on the left side of the object is expanding. Please see the pictures attached (movingCone_initial.png and movingCone_last.png)

movingCone_initial.jpg

movingCone_last.jpg


After that, I tried to apply the same principles to a hull traveling through calm water making a 45 degree angle with the waves. I want to make the hull move 4 times of its length, but my run crashes a little bit after the start. I think that is because the distortion of the mesh. Please see the pictures attached (ship_initial and ship_last)

ship_initial.jpg

ship_last.jpg


Do you know if there is a way to overcome that distortion problem? (Like updating and recreating the mesh in each step).

Or should I try a completely different method?


Thank you very much for your help in advance,

Kilroy
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Old   May 17, 2013, 19:28
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Hi Kilroy,

I do not think that you will be successful in actually moving the mesh, unless you apply some sliding of the mesh lines on/off the hull as it progress through the computational domain. This calls for topological changes (which are supported in waves2Foam, by the way). This will probably be some work from your side, as I do not think that the existing methods will be directly applicable.

A completely different approach would be mesh overlay, where you have a ship mesh moving in a static background mesh, however, to my knowledge this is still closed source for OF. The only version that I have seen was shown in a presentation at the Gothenburg conference.

Another thing is the additional amount of computational cells, since your domain will then have to be somewhat larger than 4 times the ship length, which will be a considerable extension compared to your present 1 ship plus relaxation zones.

Kind regards

Niels
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Old   May 20, 2013, 05:22
Post logarithmic profile at inlet
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Hi Niels,

I am simulating a steady current case in an open channel. Currently, I am using waveVelocity to generate a uniform velocity inlet, however, the logarithmic profile in the domain is under-developed. I am just wondering can wave2foam generate a logarithmic velocity profile at the inlet?

Many thanks in advance.

Sophie
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Old   May 20, 2013, 06:08
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Hi Sophie,

Yes, it should be possible to make a logarithmic velocity profile, but it requires that you implement it yourself.

Have a look in the source code at

Code:
waves2Foam/src/waveTheories/current/potentialCurrent
and you will see that it is exceptionally easy to extend the code with such a velocity profile.

Kind regards

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