CDNozzle1_CL
CDNozzle1_CL provides a model of a converging-diverging (CD) nozzle capable of producing supersonic flow. This model assumes isentropic flow throughout the nozzle with no shocks. The fluid can be any ideal gas or real fluid within the EES database. If a real fluid is specified, an option is provided for a real gas or ideal gas analysis. The ideal gas analysis often provides an accurate representation of the flow with less computation and more stability.
CALL CDNozzle1_CL(Gas$,T_in, P_in, Vel_in, A_throat, A_out, M_guess, Type$: T_out, P_out ,M_out, Vel_out)
Inputs:
Gas$ Name of a gas in the EES database
T_in: inlet temperature (C, K, F, R)
P_in: inlet pressure (bar, atm, Pa, kPa, MPa)
Vel_in: inlet velocity (m/s, ft/s)
P_out: outlet pressure (bar, atm, Pa, kPa, MPa)
A_throat area of the nozzle throat (m, ft)
A_out area of the nozzle outlet or specified position along the flow length (m, ft)
M_guess guess for the outlet Mach number. Use a value <1 for subsonic flow and >1 for supersonic flow
Type$ either 'ideal' or 'real'; a real gas analysis occurs if Gas$ is a real fluid and Type$='real'; otherwise an ideal gas analysis is provided.
Outputs:
T_out: outlet temperautre (C, K, F, R)
P_in: outlet pressure (bar, atm, Pa, kPa, MPa)
M_out Mach number at the outlet
Vel_out: inlet velocity (m/s, ft/s)
Notes: Since the compressible flow equations in the nozzle have two solution (subsonic and supersonic) it is necessary to specify which solution is desired with M_guess
Example:
The diameter in mm (D_mm) of a nozzle as a function of location along the flow direction x_mm have been entered into the Parametric table shown below. The nozzle throat is located at x_mm=4.5 mm. The inlet conditions are 25 C and 2200 kPa. Air_ha (real fluid) is chosen as the gas and a real fluid analysis (Type$='real') is performed. Results are shown in the Parametric table.
$Load Component Library
$UnitSystem SI Mass J K kPa
$TabStops 0.2 4
$Varinfo T_in, T_out Units=K
$VarInfo P_in, P_out Units=kPa
$VarInfo Vel_in, Vel_out Units=m/s
$VarInfo A_throat, A_out Units=m^2
$VarInfo D_mm Units=mm
$VarInfo D Units=m
Gas$='air_ha' "air is an ideal gas; air_ha is a real gas"
D_throat=6.132 [mm]*Convert(mm,m) "throat diameter"
T_in=ConvertTemp(C,K,25[C]) "inlet temperature"
P_in=2200 [kPa] "inlet pressure"
A_throat=pi*D_throat^2/4 "critical area"
D=D_mm*Convert(mm,m) "diameter"
A_out=pi*D^2/4 "area"
Type$='real' "ideal or real"
Vel_in=1 [m/s] "velocity at nozzle inlet"
CALL CDNozzle1_CL(Gas$,T_in, P_in, Vel_in, A_throat, A_out, M_guess, Type$: T_out, P_out ,M_out, Vel_out)
