The mass flow rate through a convergent nozzle is a crucial parameter in fluid dynamics, especially in the context of compressible flows like those found in rocket nozzles or jet engine exhausts.
A convergent nozzle is a geometric configuration where the cross-sectional area of the flow decreases in the direction of the flow. In the context of a rocket or jet engine, the nozzle is where high-velocity, high-temperature gases are expelled to generate thrust.
In high-speed nozzle flows, the flow is often assumed to be isentropic (adiabatic and reversible). This allows us to use isentropic relations to relate the different flow parameters. For example, the velocity of the flow () in terms of the local speed of sound () is given by:
V=M*a
which gives,
where,
- ṁ is the mass flow rate of the nozzle
- is the density of the exhaust gases at the throat
- A is the throat nozzle area
- M is the Mach Number
- a is the speed of sound in the medium