U-RANS in FLUENT
 

Hi,
I working on unsteady compressible jet flows using U-RANS in FLUENT.
My problem is that I can not resolve the unsteady behavior in a flow which based on many papers and another solver that we have is definitely unsteady.
I have played around quite a lot with the grid, solver accuracy and multigrid coefficients. I wonder if anyone has tries to use U-RANS in FLUENT and have experienced the same difficulties?

I am really confused since I do not know whether I am making some mistake or it is FLUENT that is too damping for unsteady jet kind of problem.