Question

State true or false. Divergent – convergent nozzles are used to achieve supersonic flow.

(a) True

(b) False

The question was asked during an online interview.

My doubt stems from Governing Equations for Quasi One Dimensional Flow in division Compressible Flow through Nozzles, Diffusers and Wind Tunnels of Aerodynamics

Answer 1

Correct option is (b) False

To explain I would say: In the case of subsonic flow, convergent nozzle leads of increased velocity using the area – velocity relation. Similarly, for supersonic flow the divergent nozzle leads to increased flow velocity. Thus, in order to obtain the supersonic flow we make use of convergent – divergent nozzle.