Pressure Question

1. Dec 7, 2005

physicsCU

Quick question from my last aero test

We are given an incompressible Cp of -0.18, the freestream V and the altitude. The question is to determine the local velocity at the Cp point.

The flow is compressible.

Can I simply do -0.18 = 1 - (VL/V0)^2 and solve VL?

Or do I need the Prandtl-Glaubert approximation of Cp = Cp_incompressible/Sqrt(1-M0^2) ?

I did it without using prandtl, but I don't know if that is ok or not. I can't seem to get a clear answer from the prof and solutions haven't been posted.

Thanks all!!!