Question

What is the coefficient of lift according to the linearized theory over a flat plate kept at an inclination of 3 degrees having a freestream Mach number of 2?

(a) 0.01

(b) 0.12

(c) 0.85

(d) 0.52

This question was posed to me in unit test.

This intriguing question comes from Linearized Pressure Coefficient topic in section Linearized and Conical Flows of Aerodynamics

Answer 1

Right option is (b) 0.12

Easy explanation: Given, M∞ = 2, ∝ = 3 = 0.052 rad

According to the linearized theory, the coefficient of lift over a flat plate is given by:

cl = \(\frac {4∝}{\sqrt {M_∞^2 – 1}}\)

Substituting the values we get

cl = \(\frac {4 × 0.052}{\sqrt {4 – 1}}\) = 0.12