strange residual of k when using realizable k-epsilon model
 

Hi Foamers,

I am using the realizable k-epsilon model. I run the k-epsilon model from the solution of the standard k-epsilon model. The solver is buoyantSimpleFoam.

However, after dozens of iterations, the residual for k drops dramatically to 1E-12. The solver also bounds k. The minimum k is 3E-16 and maximum k is 0.2. There should be something wrong, but I have no idea where the problem is.

I appreciate help from you.

Depending on your geometry, this may be correct. k represents the kinetic turbulent energy. If you have a undisturbed free stream in most of your area, there is no turbulent energy.

Hi Uwe,

Thank you for your reply.

The realizable k-epsilon is run from the solution of standard k-epsilon model, where the residual for k is around 1E-6.

I don't know why there is such a big difference.