Question

The linearized perturbation velocity potential equation for supersonic flow takes form of which of these partial differential equations?

(a) Elliptic

(b) Hyperbolic

(c) Parabolic

(d) Linear

I got this question in a national level competition.

This question is from Linearized Supersonic Flow topic in section Linearized and Conical Flows of Aerodynamics

Answer 1

Correct option is (b) Hyperbolic

To explain: The linearized perturbation velocity potential equation for supersonic flow differs with the subsonic flow in the type of partial differential equation formed. The equation for supersonic flow given as below which is in the form of hyperbolic partial differential equation.

λ^2ϕxx + ϕyy = 0