Question

The flow properties of the moving wave depends on which property/properties?

(a) Direction

(b) Time

(c) Both direction and time

(d) Temperature

The question was asked in an internship interview.

My question comes from Moving Normal Shock Waves topic in section Unsteady Wave Motion of Aerodynamics

Answer 1

Correct option is (c) Both direction and time

To explain I would say: Moving shock wave is an example of unsteady flow which means that all its flow properties such as density, velocity, temperature are a function of both the direction (x) and time (t). Although stationary shock wave are steady flow, thus the flow properties are only a function of direction (x).