As a rule of a thumb, can I say that when running an unsteady simulation in any turbulence model, when I achieve a periodic oscillation in my residuals and in mass-weighted average plots, etc. solution has converged?

If not, this means that mass-weighted average quantities must flatten like in steady simulations?

Thanks!

Monitor a parameter like Lift or Drag, when they converge then it means your solution has converged.

Matt

But in unsteady these parameters I don't think they keep constant: won't they be fluctuating according to also fluctuating velocity and pressure fields?

You reach a point where they do not oscillate much hence you can assume that the solution has converged. However, you can still write a PERL script to average out the final results.

Matt

OK Matt, many thanks!

Then If I've understood well, when I am in unsteady problems I will get the convergence when my parameters of the flow (mass-weighted average and/or drag-coeff, etc.) have a (little) periodic oscillation, doesn't it?