[shipman]

Dear Foam Users,

I am trying to make cavitation simulation inside the nozzle. Before, I have used interphasechangeFoam, but i couldnt get satisfied result (http://www.cfd-online.com/Forums/ope...oam-error.html) so i decided to use bubbleFoam. As you can see above link my domain has inlet and outlet which are totally liquid and gas phase has formed due to sharped edge inside of throat. Therefore, i couldnt understand how can i set the 0/alpha file. as far as i understood from the tutorial of bubble foam, alpha shows dispersed phase volume fraction and if it is =1 totally vapor phase, if it is =0 totally liquid phase..(if i am wrong please correct me)

In the bubblefoam tutorial, alpha set 0.5 at the inlet, but in my case there is no vapor at the inlet and outlet, only liquid, and when i set the internalField as 1, it gives error. Finally i set as follows but it gives again error as below.

0/alpha

internalField   uniform 0.33;

boundaryField
{
         inlet
    {
         type            zeroGradient;
    }

    outlet
    {
        type            inletOutlet;
        inletValue      uniform 0;
        value           uniform 0;
    }

    wall
    {
      type            zeroGradient;
    }

Error:

Courant Number mean: 2.08485e-06 max: 2.88724
deltaT = 1.93606e-13
--> FOAM Warning : 
    From function Time::operator++()
    in file db/Time/Time.C at line 1010
    Increased the timePrecision from 7 to 8 to distinguish between timeNames at time 0.000977614
Time = 0.00097761364

Max Ur Courant Number = 4.58454
DILUPBiCG:  Solving for alpha, Initial residual = 2.3853e-07, Final residual = 2.4793e-11, No Iterations 1
DILUPBiCG:  Solving for alpha, Initial residual = 3.6304e-08, Final residual = 7.48358e-12, No Iterations 1
Dispersed phase volume fraction = 0.302299  Min(alpha) = -0.00125876  Max(alpha) = 0.974554
DICPCG:  Solving for p, Initial residual = 0.990648, Final residual = 0.0236273, No Iterations 2
time step continuity errors : sum local = 8.98747e+06, global = -0.118401, cumulative = -0.118401
DICPCG:  Solving for p, Initial residual = 0.765502, Final residual = 9.40804e-11, No Iterations 255
time step continuity errors : sum local = 0.00104674, global = 1.93034e-05, cumulative = -0.118381
DILUPBiCG:  Solving for epsilon, Initial residual = 0.999851, Final residual = 3.52247e-11, No Iterations 22
DILUPBiCG:  Solving for k, Initial residual = 0.999992, Final residual = 9.42252e-11, No Iterations 812
ExecutionTime = 48734.2 s  ClockTime = 49906 s

Courant Number mean: 2.12678e+06 max: 1.26082e+12
deltaT = 1.53556e-26
--> FOAM Warning : 
    From function Time::operator++()
    in file db/Time/Time.C at line 1010
    Increased the timePrecision from 8 to 9 to distinguish between timeNames at time 0.000977614
Time = 0.000977613642

Max Ur Courant Number = 0.22989
DILUPBiCG:  Solving for alpha, Initial residual = 5.25024e-08, Final residual = 5.06368e-12, No Iterations 1
DILUPBiCG:  Solving for alpha, Initial residual = 5.5521e-10, Final residual = 1.13295e-13, No Iterations 1
Dispersed phase volume fraction = 0.302299  Min(alpha) = -0.00118087  Max(alpha) = 0.974554
DICPCG:  Solving for p, Initial residual = 0.999998, Final residual = 0.0634955, No Iterations 2
time step continuity errors : sum local = 3.66498e-09, global = -4.6327e-10, cumulative = -0.118381
DICPCG:  Solving for p, Initial residual = 1.32929e-05, Final residual = 9.55182e-11, No Iterations 153
time step continuity errors : sum local = 1.90516e+08, global = -465408, cumulative = -465408
DILUPBiCG:  Solving for epsilon, Initial residual = 0.17329, Final residual = 17.7977, No Iterations 1001
DILUPBiCG:  Solving for k, Initial residual = 1, Final residual = 1.11326e+25, No Iterations 1001
ExecutionTime = 48755.2 s  ClockTime = 49927 s

Courant Number mean: 2.10289e+13 max: 1.51796e+19
deltaT = 1.01159e-46
--> FOAM Warning : 
    From function Time::operator++()
    in file db/Time/Time.C at line 1010
    Increased the timePrecision from 9 to 10 to distinguish between timeNames at time 0.000977614
Time = 0.0009776136421

Max Ur Courant Number = 3.24247
DILUPBiCG:  Solving for alpha, Initial residual = 1.64427e-08, Final residual = 1.00091e-11, No Iterations 6
DILUPBiCG:  Solving for alpha, Initial residual = 1.10356e-07, Final residual = 9.84183e-11, No Iterations 3
Dispersed phase volume fraction = 0.302299  Min(alpha) = -0.00118084  Max(alpha) = 0.974554
[4] [9] #0  Foam::error::printStack(Foam::Ostream&)#0  [3] #0  Foam::error::printStack(Foam::Ostream&)Foam::error::printStack(Foam::Ostream&) in "/opt/openfoam211/platforms/linux64GccDPOpt/lib/libOpenFOAM.so"
[3] #1  Foam::sigFpe::sigHandler(int) in "/opt/openfoam211/platforms/linux64GccDPOpt/lib/libOpenFOAM.so"
[9] #1  Foam::sigFpe::sigHandler(int) in "/opt/openfoam211/platforms/linux64GccDPOpt/lib/libOpenFOAM.so"
[4] #1  Foam::sigFpe::sigHandler(int) in "/opt/openfoam211/platforms/linux64GccDPOpt/lib/libOpenFOAM.so"
[4] #2   in "/opt/openfoam211/platforms/linux64GccDPOpt/lib/libOpenFOAM.so"
[9] #2   in "/lib/x86_64-linux-gnu/libc.so.6"
[4] #3  Foam::PCG::solve(Foam::Field<double>&, Foam::Field<double> const&, unsigned char) const in "/opt/openfoam211/platforms/linux64GccDPOpt/lib/libOpenFOAM.so"
[3] #2   in "/lib/x86_64-linux-gnu/libc.so.6"
[9] #3  Foam::PCG::solve(Foam::Field<double>&, Foam::Field<double> const&, unsigned char) const in "/opt/openfoam211/platforms/linux64GccDPOpt/lib/libOpenFOAM.so"
[9] #4  Foam::fvMatrix<double>::solve(Foam::dictionary const&) in "/lib/x86_64-linux-gnu/libc.so.6"
[3] #3  Foam::PCG::solve(Foam::Field<double>&, Foam::Field<double> const&, unsigned char) const in "/opt/openfoam211/platforms/linux64GccDPOpt/lib/libOpenFOAM.so"
[3] #4  Foam::fvMatrix<double>::solve(Foam::dictionary const&) in "/opt/openfoam211/platforms/linux64GccDPOpt/lib/libOpenFOAM.so"
[4] #4  Foam::fvMatrix<double>::solve(Foam::dictionary const&) in "/opt/openfoam211/platforms/linux64GccDPOpt/lib/libfiniteVolume.so"
[3] #5   in "/opt/openfoam211/platforms/linux64GccDPOpt/lib/libfiniteVolume.so"
[9] #5   in "/opt/openfoam211/platforms/linux64GccDPOpt/lib/libfiniteVolume.so"
[4] #5  

[9]  in "/opt/openfoam211/platforms/linux64GccDPOpt/bin/bubbleFoam"
[9] #6  __libc_start_main
[3]  in "/opt/openfoam211/platforms/linux64GccDPOpt/bin/bubbleFoam"
[3] #6  __libc_start_main in "/lib/x86_64-linux-gnu/libc.so.6"
[3] #7   in "/lib/x86_64-linux-gnu/libc.so.6"
[9] #7  [4]  in "/opt/openfoam211/platforms/linux64GccDPOpt/bin/bubbleFoam"
[4] #6  __libc_start_main in "/lib/x86_64-linux-gnu/libc.so.6"
[4] #7  


[3]  in "/opt/openfoam211/platforms/linux64GccDPOpt/bin/bubbleFoam"
[efs-desktop:28090] *** Process received signal ***
[efs-desktop:28090] Signal: Floating point exception (8)
[efs-desktop:28090] Signal code:  (-6)
[efs-desktop:28090] Failing at address: 0x3e800006dba
[9]  in "/opt/openfoam211/platforms/linux64GccDPOpt/bin/bubbleFoam"
[efs-desktop:28096] *** Process received signal ***
[efs-desktop:28096] Signal: Floating point exception (8)
[efs-desktop:28096] Signal code:  (-6)
[efs-desktop:28096] Failing at address: 0x3e800006dc0
[efs-desktop:28096] [ 0] /lib/x86_64-linux-gnu/libc.so.6(+0x364c0) [0x7f8f0c1664c0]
[efs-desktop:28096] [ 1] /lib/x86_64-linux-gnu/libc.so.6(gsignal+0x35) [0x7f8f0c166445]
[efs-desktop:28096] [ 2] /lib/x86_64-linux-gnu/libc.so.6(+0x364c0) [0x7f8f0c1664c0]
[efs-desktop:28096] [ 3] /opt/openfoam211/platforms/linux64GccDPOpt/lib/libOpenFOAM.so(_ZNK4Foam3PCG5solveERNS_5FieldIdEERKS2_h+0xd0d) [0x7f8f0d19359d]
[efs-desktop:28096] [ 4] /opt/openfoam211/platforms/linux64GccDPOpt/lib/libfiniteVolume.so(_ZN4Foam8fvMatrixIdE5solveERKNS_10dictionaryE+0x137) [0x7f8f0e228307]
[efs-desktop:28096] [ 5] bubbleFoam() [0x432d9f]
[efs-desktop:28096] [ 6] /lib/x86_64-linux-gnu/libc.so.6(__libc_start_main+0xed) [0x7f8f0c15176d]
[efs-desktop:28096] [ 7] bubbleFoam() [0x43ac7d]
[efs-desktop:28096] *** End of error message ***
[efs-desktop:28090] [ 0] /lib/x86_64-linux-gnu/libc.so.6(+0x364c0) [0x7f927c8054c0]
[efs-desktop:28090] [ 1] /lib/x86_64-linux-gnu/libc.so.6(gsignal+0x35) [0x7f927c805445]
[efs-desktop:28090] [ 2] /lib/x86_64-linux-gnu/libc.so.6(+0x364c0) [0x7f927c8054c0]
[efs-desktop:28090] [ 3] /opt/openfoam211/platforms/linux64GccDPOpt/lib/libOpenFOAM.so(_ZNK4Foam3PCG5solveERNS_5FieldIdEERKS2_h+0xd0d) [0x7f927d83259d]
[efs-desktop:28090] [ 4] /opt/openfoam211/platforms/linux64GccDPOpt/lib/libfiniteVolume.so(_ZN4Foam8fvMatrixIdE5solveERKNS_10dictionaryE+0x137) [0x7f927e8c7307]
[efs-desktop:28090] [ 5] bubbleFoam() [0x432d9f]
[efs-desktop:28090] [ 6] /lib/x86_64-linux-gnu/libc.so.6(__libc_start_main+0xed) [0x7f927c7f076d]
[efs-desktop:28090] [ 7] bubbleFoam() [0x43ac7d]
[efs-desktop:28090] *** End of error message ***
[4]  in "/opt/openfoam211/platforms/linux64GccDPOpt/bin/bubbleFoam"
[efs-desktop:28091] *** Process received signal ***
[efs-desktop:28091] Signal: Floating point exception (8)
[efs-desktop:28091] Signal code:  (-6)
[efs-desktop:28091] Failing at address: 0x3e800006dbb
[efs-desktop:28091] [ 0] /lib/x86_64-linux-gnu/libc.so.6(+0x364c0) [0x7f3618f274c0]
[efs-desktop:28091] [ 1] /lib/x86_64-linux-gnu/libc.so.6(gsignal+0x35) [0x7f3618f27445]
[efs-desktop:28091] [ 2] /lib/x86_64-linux-gnu/libc.so.6(+0x364c0) [0x7f3618f274c0]
[efs-desktop:28091] [ 3] /opt/openfoam211/platforms/linux64GccDPOpt/lib/libOpenFOAM.so(_ZNK4Foam3PCG5solveERNS_5FieldIdEERKS2_h+0xd19) [0x7f3619f545a9]
[efs-desktop:28091] [ 4] /opt/openfoam211/platforms/linux64GccDPOpt/lib/libfiniteVolume.so(_ZN4Foam8fvMatrixIdE5solveERKNS_10dictionaryE+0x137) [0x7f361afe9307]
[efs-desktop:28091] [ 5] bubbleFoam() [0x432d9f]
[efs-desktop:28091] [ 6] /lib/x86_64-linux-gnu/libc.so.6(__libc_start_main+0xed) [0x7f3618f1276d]
[efs-desktop:28091] [ 7] bubbleFoam() [0x43ac7d]
[efs-desktop:28091] *** End of error message ***
--------------------------------------------------------------------------
mpirun noticed that process rank 3 with PID 28090 on node efs-desktop exited on signal 8 (Floating point exception).

My another question is how to set da and db in constant/transportproperties. when i used interphasechange foam, i always set the initial bubble dia=2e-6 (in bubblefoam i think this is da), but i dont know how can i set the db for water liquid.

Any help will be very appreciated.

Thanks in advance.

[shipman]

nobody has any idea about this problem in bubblefoam?

And one more question is that can bubblefoam be used for cavitation modelling?

thanks...

[wyldckat]

Hi shipman,

Unfortunately there isn't enough information in your posts to make an educated guess on what exactly needs to be fixed. At least not with my experience on the topic, which isn't much.

All I can do is suggest the following:

1. Do not try to solve the final problem in a single step. This is OpenFOAM, this is not any other commercial CFD application that has all of the right parts in the right places at the click of the mouse and that tells you what might be wrong and where to look to solve the problem.
2. You should start small. Start with the tutorials in OpenFOAM and then gradually increase the complexity of the problem, based on those tutorials.
3. There are too many variables at work:
   1. Mesh resolution
   2. Geometry complexity, including the size of the geometry/domain
   3. Cavitation issues and/or phase changing issues
   This means that if you jump into the final problem without addressing one issue at a time, you will very unlikely succeed in the near future. Which is why you should take one small step at a time, to understand how to use OpenFOAM and to confirm which solver you need to use.
4. Last but not least, I suggest that you have a look into this blog post, that gives some very important tips on how to handle CFD problems/cases: http://www.symscape.com/blog/cfd-tip...ctive-new-year

Best regards,
Bruno