Cyclone Separator steady dpm in transient solution
 

I am very new to fluent so any help would be much appreciated.

I am running an analysis of a cyclone separator. Inlet is velocity inlet, outlet is pressure outlet.

I run 200 k-e iterations before changing to 4000 RSM iterations at which point the residuals exhibit some periodic oscillations.

At this point I change to transient and reduce the timestep until convergence occurs.

If I am going to use DPM with the unsteady particle tracks function unchecked, is there a way to determine how many timesteps I need to simulate before the steady DPM solver will give a good picture of the flow to inject particles into.

Or can I inject particles at any timestep that has converged, for example the first timestep for which convergence occurs.