Question

3D relieving effect is a consequence of which of these flows?

(a) Flow over a wedge

(b) Flow over a flat – plate

(c) Flow over a cone

(d) Flow over a flat plate kept at 90 degrees

I had been asked this question in an internship interview.

The above asked question is from Physical Aspects of Conical Flow topic in portion Linearized and Conical Flows of Aerodynamics

Answer 1

The correct choice is (c) Flow over a cone

Explanation: Since the pressure over the conical surface is not constant unlike the flow over the wedge, the streamlines tend to curve behind the shock wave. The 3 – dimensional nature of conical flow provides the streamlines with an extra space relieving any obstruction from the surface of the body. This is known as 3D relieving effect.