What should I do for the CDI

Jen

For the unsteady turbulent simulations, do I have to insert the Core Dynamic Instability in order to see the transient behavior such as Vortex Shedding? So far, I did not see the necessary vortex in my early stage of simulations? Meshes may not be sufficient enough for my limited computational resources. I suppose that the turbulent itself should provide enough instability to see the unsteady behavior. Thank you very much for the input.