[karthik1414]

hey everyone,

for a horizontal two phase stratified flow with twoPhaseEulerFoam and the following error message shows up :

[0] #0 Foam::error::printStack(Foam::Ostream&) in "/opt/products/OpenFOAM/OpenFOAM-1.7.0/lib/linux64GccDPOpt/libOpenFOAM.so"
[0] #1 Foam::sigFpe::sigFpeHandler(int) in "/opt/products/OpenFOAM/OpenFOAM-1.7.0/lib/linux64GccDPOpt/libOpenFOAM.so"
[0] #2 ?? in "/lib/libc.so.6"
[0] #3 Foam::PCG::solve(Foam::Field<double>&, Foam::Field<double> const&, unsigned char) const in "/opt/products/OpenFOAM/OpenFOAM-1.7.0/lib/linux64GccDPOpt/libOpenFOAM.so"
[0] #4 Foam::fvMatrix<double>::solve(Foam::dictionary const&) in "/opt/products/OpenFOAM/OpenFOAM-1.7.0/lib/linux64GccDPOpt/libfiniteVolume.so"
[0] #5 main in "/opt/products/OpenFOAM/OpenFOAM-1.7.0/applications/bin/linux64GccDPOpt/twoPhaseEulerFoam"
[0] #6 __libc_start_main in "/lib/libc.so.6"
[0] #7 Foam::regIOobject::writeObject(Foam::IOstream::str eamFormat, Foam::IOstream::versionNumber, Foam::IOstream::compressionType) const in "/opt/products/OpenFOAM/OpenFOAM-1.7.0/applications/bin/linux64GccDPOpt/twoPhaseEulerFoam"


i had done it previously with vof and interfoam and it was running fine.
I also tried using a finer mesh from around 40000 to 112000 (with twoPhaseEulerFoam), but still it crashes with the same error message.
It would be great to get your suggestions on this one :)

regards,
Karthik

[freemankofi]

Karthik,
Since you didn't give much information, I assumed that it didn't even start. Therefore, it'sn't the number of mesh issue rather the issue of 'problem setup'.

Check to make sure that the flow is setup right including specifying all required BCs & ICs and the coupling forces. what kind of stratified flow: is it laminar/turbulence? solid-liquid or liquid-gas or ? are you using kinetic theory or not, etc.?

If you need help, please try to give much information so that one can assist you on that. Note that both vof and interfoam are different from twoPhaseEulerFoam, since the former are relatively simple and assumed a "homogeneous" flow with NO fluids 'coupling'. The later required a bit time to setup and demand some understanding of the problem at hand.

best regards,
Freeman

[karthik1414]

I was trying to simulate a horizontal, turbulent, stratified two-phase flow (liquid- gas) using twoPhaseEulerFoam. I am pretty sure that my BCs are correct.
First, I tried using funkySetFields to generate the internal fields for the phase velocities and then I tried taking the internal field as uniform.
Both the times it did not work, so I tried changing the velocities of the two phases to zero and just let the two phases flow in the domain, but still it was not working.
I tried changing the scheme from Euler to steadyState, but it showed errors and crashed. (The courant number was oscillating from 300 to 0.08, eventhough limitation of 0.1 was imposed)

[freemankofi]

I haven't used "funkySetFields" and neither have I used twoPhaseEulerFoam for liquid-gas before, therefore I can't comment on them. However, I have used it for solid-liquid and it works for both horizontal and vertical pipe flows.

I believe the best way is start something simple. For example, the same flow through through a horizontal rectangular channel. With this case, you can simply take 3D fluidized bed tutorial and modified it. If that works, then you can compare with your case setup and see where you might have gone wrong.

Quote "First, I tried using funkySetFields to generate the internal fields for the phase velocities and then I tried taking the internal field as uniform."
Note that, you can't simply modified 'SetFields' without modifying '0/alpha' file to match it.

Quote "Both the times it did not work, so I tried changing the velocities of the two phases to zero and just let the two phases flow in the domain, but still it was not working."

I don't think I got above right...how do you have "zero velocities" for both phases and expect a flow? did you specify pressure instead? or you meant initialized them with zero velocities instead of using "SetFields" with values. Once again, I suggest that you use twoPhaseEulerFoam to solve a dispersed flow first. twoPhaseEulerFoam is more suited for flows where gravity/drag are more prominent. In other words, if you domain doesn't have bubbles/droplets/solid particles, you're wasting your damned time with twoPhaseEulerFoam, just used VOF or interFOAM

I hope that helps.

[karthik1414]

thank you for the reply, Mr.Freeman, will try it out