Reply To: Relying on Global Courant Number Larger Than Unity

[Rob]

If your results are converged at the end of each time step then you're probably going to get an accurate result (mesh etc assumed to be good). 

Be careful with blind adherence to a number. The highest courant number could be in a region with near enough zero gradients so won't overly effect stability. Setting too high a value in the adaptive stepping may well cause you problems, too low and it'll take ages to march through time. If you're looking at updating cell position (rotating parts) if you jump cells in a time step you risk blade wake/tip effects not being picked up across the interface: courant number will be big and your result may be rubbish.