steady unsteady

subhra

Hi, I am a graduate student..Can somebody help me find an answer to following two doubts I have:

1) Do Problems that give rise to physical instabilities will always give rise to numerical instability?

2) What can be the expected consequence of trying to solve numerically the following laminar problem with a steady-state solver?

Flow in a 2-D channel with a cylinder installed at its center(Re=200, say)

An actual experiment with shows a periodic shedding of vortices, the solution never gets time-independent..