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-   -   becker bubble column with twoPhaseEulerFoam (http://www.cfd-online.com/Forums/openfoam-solving/98212-becker-bubble-column-twophaseeulerfoam.html)

 GerhardHolzinger March 6, 2012 03:28

becker bubble column with twoPhaseEulerFoam

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Hello,

I am quite new to OF and I am trying to simulate a bubble column. The setting is described in publications of S. Becker who did measurements as well as simulations.

In Pfleger et al. (1999) it is stated that the continuous phase (water) is modelled laminar or turbulent while the dispersed phase (air) is always modelled laminar.

How is it possible in OF to model only one phase turbulent?

Pfleger et al. further conclude that modelling the continuous phase fits experimental data better than modelling it laminar.

I did a simulation modelling all phases laminar and also modelling all phases turbulent. In my solutions only the laminar case shows the expected oscillation of the bubble plume.

 chittipo August 26, 2012 11:26

Did you solve this issue ?

why don't there are any oscillations with turbulence ?

 Mat_fr August 30, 2012 09:01

I suppose it's quite late for answering, but anyway, I think you should play with the turbulent response coefficient Ct in transportProperties to differentiate the turbulence behaviour of both phases.

Best,

Mat

 Jonas Ansoni November 21, 2013 12:45

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Hi!!

I'm trying to use the twoPhaseEulerFoam to solve a problem as described on the case1 file (Download files). However, I am not able to get results because deltaT is too small.

Code:

```Courant Number mean: 1.76078e-05 max: 0.215443 Max Ur Courant Number = 0.517251 deltaT = 1.8695e-108 --> FOAM Warning :     From function Time::operator++()     in file db/Time/Time.C at line 937     Increased the timePrecision from 6175 to 6176 to distinguish between timeNames at time 0.0223074 Time = 0.02230736969663438262756471885950304567813873291015625 DILUPBiCG:  Solving for alpha, Initial residual = 1.24818e-08, Final residual = 3.00309e-20, No Iterations 1 Dispersed phase volume fraction = 0.000706992  Min(alpha) = -2.22442e-06  Max(alpha) = 0.500588 DILUPBiCG:  Solving for alpha, Initial residual = 1.10523e-09, Final residual = 3.94419e-24, No Iterations 1 Dispersed phase volume fraction = 0.000706992  Min(alpha) = -2.22442e-06  Max(alpha) = 0.500588 [7] #0  Foam::error::printStack(Foam::Ostream&) in "/opt/openfoam201/platforms/linux64GccDPOpt/lib/libOpenFOAM.so" [7] #1  Foam::sigFpe::sigHandler(int) in "/opt/openfoam201/platforms/linux64GccDPOpt/lib/libOpenFOAM.so" [7] #2  in "/lib/libc.so.6" [7] #3  Foam::GAMGSolver::scalingFactor(Foam::Field<double>&, Foam::Field<double> const&, Foam::Field<double> const&, Foam::Field<double> const&) const in "/opt/openfoam201/platforms/linux64GccDPOpt/lib/libOpenFOAM.so" [7] #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/openfoam201/platforms/linux64GccDPOpt/lib/libOpenFOAM.so" [7] #5  Foam::GAMGSolver::Vcycle(Foam::PtrList<Foam::lduMatrix::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/openfoam201/platforms/linux64GccDPOpt/lib/libOpenFOAM.so" [7] #6  Foam::GAMGSolver::solve(Foam::Field<double>&, Foam::Field<double> const&, unsigned char) const in "/opt/openfoam201/platforms/linux64GccDPOpt/lib/libOpenFOAM.so" [7] #7  Foam::fvMatrix<double>::solve(Foam::dictionary const&) in "/opt/openfoam201/platforms/linux64GccDPOpt/lib/libfiniteVolume.so" [7] #8  [7]  in "/opt/openfoam201/platforms/linux64GccDPOpt/bin/twoPhaseEulerFoam" [7] #9  __libc_start_main in "/lib/libc.so.6" [7] #10  [7]  in "/opt/openfoam201/platforms/linux64GccDPOpt/bin/twoPhaseEulerFoam" [pegasus:03885] *** Process received signal *** [pegasus:03885] Signal: Floating point exception (8) [pegasus:03885] Signal code:  (-6)```
However, I'm generating the mesh using the SALOME (tetrahedral - NETGEN) (checkMesh ok). I tested a tetrahedral mesh in the same Gerhard's example and the problem occurred too.
Someone could tell me if the problem is the type of mesh or have another problem in my test case?

Best regards,
Jonas

 sharonyue November 25, 2013 01:53

Quote:
 Originally Posted by Jonas Ansoni (Post 462964) Hi!! I'm trying to use the twoPhaseEulerFoam to solve a problem as described on the case1 file (Download files). However, I am not able to get results because deltaT is too small. Code: ```Courant Number mean: 1.76078e-05 max: 0.215443 Max Ur Courant Number = 0.517251 deltaT = 1.8695e-108 --> FOAM Warning :     From function Time::operator++()     in file db/Time/Time.C at line 937     Increased the timePrecision from 6175 to 6176 to distinguish between timeNames at time 0.0223074 Time = 0.02230736969663438262756471885950304567813873291015625 DILUPBiCG:  Solving for alpha, Initial residual = 1.24818e-08, Final residual = 3.00309e-20, No Iterations 1 Dispersed phase volume fraction = 0.000706992  Min(alpha) = -2.22442e-06  Max(alpha) = 0.500588 DILUPBiCG:  Solving for alpha, Initial residual = 1.10523e-09, Final residual = 3.94419e-24, No Iterations 1 Dispersed phase volume fraction = 0.000706992  Min(alpha) = -2.22442e-06  Max(alpha) = 0.500588 [7] #0  Foam::error::printStack(Foam::Ostream&) in "/opt/openfoam201/platforms/linux64GccDPOpt/lib/libOpenFOAM.so" [7] #1  Foam::sigFpe::sigHandler(int) in "/opt/openfoam201/platforms/linux64GccDPOpt/lib/libOpenFOAM.so" [7] #2  in "/lib/libc.so.6" [7] #3  Foam::GAMGSolver::scalingFactor(Foam::Field&, Foam::Field const&, Foam::Field const&, Foam::Field const&) const in "/opt/openfoam201/platforms/linux64GccDPOpt/lib/libOpenFOAM.so" [7] #4  Foam::GAMGSolver::scalingFactor(Foam::Field&, Foam::lduMatrix const&, Foam::Field&, Foam::FieldField const&, Foam::UPtrList const&, Foam::Field const&, unsigned char) const in "/opt/openfoam201/platforms/linux64GccDPOpt/lib/libOpenFOAM.so" [7] #5  Foam::GAMGSolver::Vcycle(Foam::PtrList const&, Foam::Field&, Foam::Field const&, Foam::Field&, Foam::Field&, Foam::Field&, Foam::PtrList >&, Foam::PtrList >&, unsigned char) const in "/opt/openfoam201/platforms/linux64GccDPOpt/lib/libOpenFOAM.so" [7] #6  Foam::GAMGSolver::solve(Foam::Field&, Foam::Field const&, unsigned char) const in "/opt/openfoam201/platforms/linux64GccDPOpt/lib/libOpenFOAM.so" [7] #7  Foam::fvMatrix::solve(Foam::dictionary const&) in "/opt/openfoam201/platforms/linux64GccDPOpt/lib/libfiniteVolume.so" [7] #8  [7]  in "/opt/openfoam201/platforms/linux64GccDPOpt/bin/twoPhaseEulerFoam" [7] #9  __libc_start_main in "/lib/libc.so.6" [7] #10  [7]  in "/opt/openfoam201/platforms/linux64GccDPOpt/bin/twoPhaseEulerFoam" [pegasus:03885] *** Process received signal *** [pegasus:03885] Signal: Floating point exception (8) [pegasus:03885] Signal code:  (-6)``` However, I'm generating the mesh using the SALOME (tetrahedral - NETGEN) (checkMesh ok). I tested a tetrahedral mesh in the same Gerhard's example and the problem occurred too. Someone could tell me if the problem is the type of mesh or have another problem in my test case? Best regards, Jonas
I think twoPhaseEulerFoam cant solve on tet mesh. You have to generate a hex mesh.

Long time ago I make a very simple test. All the settings are the same expect that one is tet the other is hex. As your expect, the tet one crushed.

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