A convergent-divergent nozzle, also known as a de Laval nozzle, is a nozzle design commonly used in rocket engines and supersonic aircraft to accelerate high-speed gases.
The mass flow rate through a convergent-divergent nozzle is the quantity of fluid passing through the nozzle per unit time. This nozzle design is particularly important for achieving supersonic flow, where the nozzle consists of a converging section followed by a diverging section. The converging part accelerates the flow to sonic speed, and the diverging section continues the acceleration to supersonic speeds.
The mass flow rate can be expressed as:
where,
- ṁ is the mass flow rate through the convergent nozzle in KGs/sec
- ρ is the density of the medium
- A is the nozzle throat area
- the velocity of the flow in terms of the local speed of sound