The air Exhaust Velocity of a nozzle inlet (V2) can be related to the air Inlet velocity of the nozzle exhaust (V1), Nozzle inlet and exhaust Area (A1 and A2) and the pressure at the nozzle entrance () by using the continuity equation and Bernoulli’s equation for steady, incompressible flow. The continuity equation is based on the principle of mass conservation, and Bernoulli’s equation expresses the conservation of energy.
The continuity equation is given by:
where:
- and are the cross-sectional areas at the nozzle entrance and exit, respectively,
- and are the velocities at the nozzle entrance and exit, respectively.
which gives
where,
- A1 is the Area of Nozzle Inlet in m2
- A2 is the Area of Nozzle Exhaust in m2
- V1 is the Inlet air Velocity in m/s
- V2 is the Exhaust Air Velocity in m/s