Modeling a sediment transport phenomena using Volume of Fluid (VOF) method for Multiphase problem and Eulerian-Larangian particle transport method for Discreet Phase Modeling (DPM). My mesh maximum skewness is around 0.5. For solver settings pressure-velocity coupling was introduced with Green-Gauss Cell Based gradient, PRESTO! pressure and Second Order Upwind momentum. I tightened all URF (Under-Relaxation Factors) to 0.1~0.2 and used 0.001 time step size.
After running the solution for some time everything looks fine in the animation but the solver fails showing "Error: Divergence detected in AMG solver: epsilon". Anyone has any idea on how it can be solved or the error can be removed?
" In the name of God, the Compassionate, the Merciful"
If you are sure your case is set up right, try the following step(are one of best answer that i found about this problem):
1- check your mesh. Is your skewness, mesh orthogonal quality, ... acceptable? 2- Initialization. Try the hybrid (FMG) initialization. 3- Under-relaxation Factors. try using 0.5 for both k & e, then ramp them up to 0.9 after 50~100 iterations. Also decrease time step or Currant Number (dependent on solver)
4- Boundary Conditions. k & e values suitable?
I'm not sure on the specifics of your case, but the error is indicating your solution is diverging, instead of converging to a solution for that time step. You stated it runs for "some time", but how many time steps does it get through before you receive the error?
I solved the divergence problem. I was injecting too much mass which apparently FLUENT can't handle as stated in the manual as one of it's limitations. I am trying with smaller amount of particle injection now.
Hi salman
One of your inputs are incorrect or incorrect range for your problem, check it
Good Luck
" In the name of God, the Compassionate, the Merciful"
If you are sure your case is set up right, try the following step(are one of best answer that i found about this problem):
1- check your mesh. Is your skewness, mesh orthogonal quality, ... acceptable? 2- Initialization. Try the hybrid (FMG) initialization. 3- Under-relaxation Factors. try using 0.5 for both k & e, then ramp them up to 0.9 after 50~100 iterations. Also decrease time step or Currant Number (dependent on solver)
4- Boundary Conditions. k & e values suitable?
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