General Unsteady solution convergence

Freeman

Hi all!

I'm starting to simulate flows over bluff bodies (with Fluent) and they seem to be unsteady, because while running steady simulations, solutions don't converge: they keep oscillating periodically.

My question is, while running an unsteady simulation, the convergence is reached when my solution parameters, as Cd, Cl, mass-weighted averages start to oscillate? And how do I suppose residuals may behave? Do they also oscillate?? If they don't, how do you see you've reached the convergence in your unsteady simualations?

Thanks a lot!