Step 6: Boundary Conditions

Boundary Conditions

1.   Set the boundary conditions for the nozzle inlet ( inlet).

Boundary Conditions inlet Edit...

(a)   Enter 0.9 atm for Gauge Total Pressure.

(b)   Enter 0.7369 atm for Supersonic/Initial Gauge Pressure.

  The inlet static pressure estimate is the mean pressure at the nozzle exit. This value will be used during the solution initialization phase to provide a guess for the nozzle velocity.

(c)   Select Intensity and Viscosity Ratio from the Specification Method drop-down list in the Turbulence group box.

(d)   Enter 1.5% for Turbulent Intensity.

(e)   Enter 10 for Turbulent Viscosity Ratio.

(f)   Click OK to close the Pressure Inlet dialog box.

2.   Set the boundary conditions for the nozzle exit ( outlet).

Boundary Conditions outlet Edit...

(a)   Enter 0.7369 atm for Gauge Pressure.

(b)   Select Intensity and Viscosity Ratio from the Specification Method drop-down list in the Turbulence group box.

(c)   Enter 1.5% for Backflow Turbulent Intensity.

(d)   Enter 10 for Backflow Turbulent Viscosity Ratio.

  If substantial backflow occurs at the outlet, you may need to adjust the backflow values to levels close to the actual exit conditions.

(e)   Click OK to close the Pressure Outlet dialog box.