1. The problem statement, all variables and given/known data What effect does a large positive dCp/dX have on the real viscous flow? This is for an airfoil design project using thin airfoil theory + vortex panel method. 3. The attempt at a solution As far as I know Viscosity is independent of pressure, so the only thing I can think of is assuming ideal gas behavior and saying that it affects the density and therefore the kinematic viscosity. However I believe that he is referring to something different, some property of a viscous flow that I haven't yet figured out. Thanks in advance.