Question

What happens when the cross – flow velocity becomes supersonic?

(a) Embedded shock waves on windward side

(b) Embedded shock waves on the leeward side

(c) Expansion shock waves on the windward side

(d) Oblique shock waves on the leeward side

The question was posed to me in my homework.

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

Answer 1

Right option is (b) Embedded shock waves on the leeward side

The explanation: When the cross – flow velocity (Vθ, Vϕ) increases and Vθ^2 + Vϕ^2 becomes greater than the square of free – stream velocity i.e. the cross – flow velocity becomes supersonic, then there is formation of embedded shock waves on the leeward portion of the cone.