How does the coefficient of pressure vary for supersonic flow as the Mach number decreases?

Increases

Decreases

Remains same

First increases, then decreases

Correct Answer : Increases

Explanation : In the supersonic regime, according to the linearized coefficient of pressure is directly proportional to the local inclination and inversely proportional to

Due to this relation, as the Mach number decreases, the coefficient of pressure increases to a point where Mach number reaches transonic regime (M = 1) where the coefficient of pressure becomes infinity.

Recently Updated in Aerodynamics Questions

Under which condition do we get the detached shock wave on a cone?

θ_c = 0

θ_c = infinty

θ_c = θ_cmax

θ_c > θ_cmax

Correct Answer : Option (D) : θ_c > θ_cmax

Explaination : For a given freestream Mach number M_∞, there exists a maximum cone angle for which if we go beyond that value, the shock wave originating at the cone’s vertex gets detached. Thus, the condition for detached shock wave is θ_c > θ_cmax.

What is the relation between maximum allowed cone angle and wedge angle for attached shock wave?

(θ_max)_wedge = (θ_max)_cone

(θ_max)_wedge > (θ_max)_cone

(θ_max)_wedge < (θ_max)_cone

(θ_max)_wedge ≈ (θ_max)_cone

Correct Answer : Option (B) : (θ_max)_wedge > (θ_max)_cone

Explaination : Due to the three-dimensional relieving effect, for a particular freestream Mach number, the maximum cone angle allowed is larger than the maximum wedge angle before the shock wave becomes detached.

Where does the flow remain supersonic in a conical surface?

Between the oblique shock and the sonic line

Between the sonic line and the conical surface

Flow is not supersonic beyond the oblique shock

Between the oblique shock and the conical surface

Correct Answer : Option (A) : Between the oblique shock and the sonic line

Explanation : The incoming flow over a cone is mostly supersonic between the surface of the cone and the oblique shock wave. Except in some cases when the half cone angle is large, flow sometimes becomes subsonic and one of the rays originating the cone’s vertex acts at the sonic line. The flow between the sonic line and the oblique shock thus remains supersonic.