Question

What is the coefficient of pressure over an airfoil at supersonic flow at Mach 2 which is inclined to the freestream at 1.4 degrees?

(a) 1.10

(b) 1.92

(c) 1.62

(d) 2.81

This question was addressed to me by my school teacher while I was bunking the class.

Enquiry is from Linearized Pressure Coefficient topic in portion Linearized and Conical Flows of Aerodynamics

Answer 1

Right choice is (c) 1.62

To explain I would say: Given, M\(_∞^2\) = 2, θ = 1.4 deg

For the supersonic flow, the linearized coefficient of pressure for small inclinations is given by:

Cp = \(\frac {2θ}{\sqrt {M_∞^2 – 1}}\)

Substituting the values, we get

Cp = \(\frac {2 × 1.4}{\sqrt {4 – 1}}\) = 1.62