Question

How are the streamlines for a conical flow behind a shock wave?

(a) Parallel throughout

(b) Curved at the beginning, parallel as surface tends to infinity

(c) Curved till surface tends to infinity

(d) Conical

This question was addressed to me during an interview.

My enquiry is from Physical Aspects of Supersonic Flow over Cones topic in section Linearized and Conical Flows of Aerodynamics

Answer 1

Right choice is (b) Curved at the beginning, parallel as surface tends to infinity

To explain I would say: For a conical flow at a given Mach number, the shock formation occurs at the vertex of the cone. The streamlines behind the shock wave are initially curved due to 3 – dimensional space unlike streamlines behind the shockwave on a wedge which is parallel. These streamlines eventually become parallel at the cone’s surface tends to infinity.