ORIGINAL: Allfat

lnewqban,

The Reynolds number for the transition from laminar to turbulent that you posted (2100-4000) is valid for pipes and enclosed flow. This is not the situation we see in an airfoil and the transition occurs somewhere in the vicinity of a reynolds number of 500,000. This is of course assuming a perfectly smooth surface, which is not really valid because no such thing exists. So in reality, the transition will be before 500,000, but the point is it is a lot higher over a plate or an airfoil than flowing through a tube.