FLUENT - Correct Prandtl Number requires consistent properties
In high-speed flows one may encounter incorrect temperature contours that are associated with incorrect Prandtl Numbers. One manifestation of this are base tempertures (behind a projectile) that are too low.
Be sure that if you have specified constant conductivity and constant specific heat, you also specify constant viscosity. Conversely, if you specify Sutherland's Law for the viscosity, you should not have the other properties be constants.