Question

There is a large gradient of entropy near the surface of the cone.

(a) True

(b) False

I got this question in an interview for job.

This is a very interesting question from Cones at Angle of Attack topic in section Three-Dimensional Flow of Aerodynamics

Answer 1

The correct option is (a) True

Easiest explanation: On the top surface of the cone, the streamlines with different entropies come together and meet at a point known as vortical singularity. This leads to an entropy layer on or above the surface of the cone depending on the relation between angle of attack and shock wave angle. This layer leads to a large gradient of entropy normal to the streamlines.