Mass discharge in a convergent–divergent steam nozzle after the throat Statement completion: In an ideally operating C–D nozzle with choked flow at the throat, the discharge (mass flow rate) of steam __________ in the divergent portion after the throat. Choose the correct completion.

Given/Definitions

• Steady 1-D nozzle, choked at throat (Mach = 1).

Concept/Approach

• For steady flow, mass flow rate ṁ = ρ A V is constant along the nozzle in the absence of leakage or extraction.
• After choking, changes in A, ρ, and V adjust so that ṁ stays the same; thus the discharge remains constant along the C–D nozzle.

Common pitfalls

• Velocity increases in the divergent section for supersonic steam, but mass flow rate does not change.

Final Answer
Remains constant