Question

In which of these conditions there’s no formation of shock wave inside a convergent – divergent nozzle?

(a) Overexpanded

(b) Underexpanded

(c) Fully expanded

(d) Fully underexpanded

I have been asked this question by my college director while I was bunking the class.

I'd like to ask this question from Nozzles topic in portion Quasi-One-Dimensional Flow of Aerodynamics

Answer 1

The correct answer is (c) Fully expanded

Explanation: When the nozzle is fully expanded i.e. when the ambient pressure is equal to the exit pressure of the nozzle, there no formation of shock waves. In case of underexpanded nozzle, there are expansion waves formed at the tip of the nozzle exit and in case of overexpanded nozzle, there’s formation of oblique shock waves at the tip.