Question

For a subsonic flow, how does the coefficient of pressure vary with increasing Mach number?

(a) Increases

(b) Decreases

(c) Remains same

(d) First increases, then decreases

I have been asked this question in final exam.

I'm obligated to ask this question of Linearized Subsonic Flow in division Linearized and Conical Flows of Aerodynamics

Answer 1

Correct answer is (a) Increases

For explanation: For a subsonic flow, the linearized coefficient of pressure is given by the equation below according to which when the Mach number is increased, the coefficient of pressure increases. Although, one thing to note is that as this Mach number is increased to unity, the coefficient of pressure reaches infinity and thus, for transonic regions, this equation fails.

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