k and epsilon were hard to converge in multiphase model of Fluent
 

Dear All,

:oMy simulation is Injecting gas into Ladle from its bottom. and my models were: VOF, k-epsilon. The time step size was 0.0001s, Residuals were all 10-5. At the beginning, about 0~0.1s, They (continuty, x-velociy, y-velociy, z-velocity, k and epsilon ) were easy to converge, but after that the k and epsilon became harder and harder to converge though the others were easy to converge. I refined my mesh, decreased the Under-Reflaxation-Factor, set MultiGrid, but It did not work.
This problem also came out when I use the other multiphase model (Mixture or Eulerian).
Do you have any idea to get through this confusion?:confused: thanks in advance.
Long