Related Resources: material science
Convergent Divergent Nozzle Flow Velocity and Area Equation and Calculator
Hydraulic & Pneumatics
Fluids Design and Engineering Data
ConvergentDivergent Nozzle Flow Velocity and Area Equation and Calculator
Throat Velocity Equation:
Values of the index n and the critical pressure ratio r, for different fluids are given in the table below.
Throat Area Equation:
Critical Pressure Ratio Equation:
Nozzle Outlet Velocity Equation:
Nozzle Outlet Area Equation:
where:
p_{1} = Inlet pressure (N / m^{2}, Pa)
v_{1} = Inlet specific volume (m^{3})
v_{c} = Outlet specific volume (m^{3})
C_{2} = Outlet velocity (m/sec)
C_{c} = Throat velocity (m/sec)
r = pressure ratio = p_{1} / p_{2}
r_{c} = critical pressure ratio
A_{2} = outlet area (m^{2})
A_{c} = throat area (m^{2})
n = index of expansion
m = mass flow rate (kg/m^{2})
Fluid 
n

r_{c}

Air (n = γ) 
1.40

0.528

Initially dry saturated steam 
1.135 
0.577

Initially superheated steam 
1.30

0.546
