[yaseen wsu]

hello
It is a good idea to increase number of iteration in steady state in my free surface model I increased till 1400 iteration but the solver does not reach 10^-4 residual. also my mesh quality is good and physics, boundary conditions are correct, so it is need to further increased or go to transient simulation. in my research I want compare the result of transient and steady simulation but unfortunately it does not convergence in steady.
thanks

[-Maxim-]

If your steady-state simulation has not converged after 1400 iterations, then it won't converge if you add more iterations. Since you are sure that your mesh and boundary conditions and physics are correct, you could change your timestep. For my steady-state simulation, I start with a large timestep and decrease it after about 150 iterations to get tighter convergence.

In case you have non-steady-state (transient) flow phenomena in your setup, only a transient simulation will help you to converge further.

[ghorrocks]

This question is an FAQ: http://www.cfd-online.com/Wiki/Ansys...gence_criteria

[yaseen wsu]

Originally Posted by -Maxim-

If your steady-state simulation has not converged after 1400 iterations, then it won't converge if you add more iterations. Since you are sure that your mesh and boundary conditions and physics are correct, you could change your timestep. For my steady-state simulation, I start with a large timestep and decrease it after about 150 iterations to get tighter convergence.

In case you have non-steady-state (transient) flow phenomena in your setup, only a transient simulation will help you to converge further.

thanks for your reply
but in steady state there is no time step, do you mean by time scale ?
please response me

[-Maxim-]

yes, it's timescale in steady-state. I would recommend 'Auto timescale' in case you're not completely sure what you are doing. You will find more information about it in the documentation and here in countless posts in this forum.