Question

Incompressible flow is a myth actually.

(a) True

(b) False

The question was asked in unit test.

This interesting question is from Flow Compressible topic in portion Normal Shock Waves of Aerodynamics

Answer 1

Right option is (a) True

For explanation: Strictly speaking, all flows are compressible i.e. incompressible flow is a myth actually. But for all practical applications, flow with Mach number < 0.3 can be assumed incompressible since the density variation is less than 5%.