 Isentropic nozzle flow

Smooth adiabatic nozzle flow without entropy production. In a steady quasi-one-dimensional ideal-gas model, $\rho uA$ and $u^2/2+c_{p}T$ are constant along the passage. A converging-diverging passage can connect subsonic and supersonic branches through a sonic throat when reservoir and back-pressure conditions select that branch.

Isentropic nozzle flow refers to the flow of a compressible fluid (such as a gas) through a nozzle under idealized conditions where the process is isentropic. An isentropic process is one that is both adiabatic (no heat transfer occurs with the surroundings) and reversible (no entropy is generated). In simpler terms, it is an idealized process that assumes no friction and no heat loss, making it highly efficient.