Question

What is the coefficient of lift according to the linearized theory over a flat plate kept at an inclination of 4 degrees having freestream Mach number of 3?

(a) 0.0987

(b) 1.231

(c) 0.857

(d) 1.362

The question was posed to me during an interview.

My enquiry is from Linearized Supersonic Flow in chapter Linearized and Conical Flows of Aerodynamics

Answer 1

The correct answer is (a) 0.0987

For explanation I would say: Given, M∞ = 3, ∝ = 4 = 0.0698 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 = \(\frac { 4× 0.0698}{\sqrt {9 – 1}} = \frac {0.2792}{2.8284}\)0.0987