You can create a fluid inlet/outlet boundary condition to specify flow conditions at a particular surface location in your model. For more information, see Chapter 30, “Fluid dynamic analyses.”
To create or edit a fluid inlet/outlet boundary condition:
Display the editor using one of the following methods:
To create a new fluid inlet/outlet boundary condition, follow the procedure outlined in “Creating boundary conditions,” Section 16.8.2 (Category: Fluid; Types for Selected Step: Fluid inlet/outlet).
To edit an existing fluid inlet/outlet boundary condition using menus or managers, see “Editing step-dependent objects,” Section 3.4.13. To edit the region to which the boundary condition is applied, see “Editing the region to which a prescribed condition is applied,” Section 16.8.4.
To specify momentum based on pressure or velocity, click the Momentum tab and do the following:
Toggle on Specify.
Select the momentum type.
Choose Pressure, and enter the fluid pressure at the inlet or outlet.
Choose Velocity, and do the following:
Click the arrow to the right of the Distribution field, and select the option of your choice from the list that appears:
Select Uniform to define a fluid boundary condition that is uniform over the region.
Select an analytical field to define a spatially varying fluid boundary condition. Only analytical fields that are valid for this boundary condition type are displayed in the selection list. Alternatively, you can click 
to create a new analytical field. (See Chapter 58, “The Analytical Field toolset,” for more information.)
Toggle on the degrees of freedom that you want to specify, and enter the velocity values.
If desired, click the arrow to the right of the Amplitude field, and select the amplitude of your choice from the list that appears. Alternatively, you can click 
to create a new amplitude. (See Chapter 57, “The Amplitude toolset,” for more information.)
To specify thermal energy settings, click the Thermal Energy tab and do the following:
Toggle on Temperature, and enter the fluid temperature at the inlet or outlet.
If desired, click the arrow to the right of the Amplitude field, and select the amplitude of your choice from the list that appears. Alternatively, you can click to create a new amplitude. (See Chapter 57, “The Amplitude toolset,” for more information.)
To specify turbulence settings, click the Turbulence tab.
If you are using the Spalart-Allmaras turbulence model in the current flow step, do the following:
Toggle on Kinematic eddy viscosity, and enter the kinematic eddy viscosity for the fluid.
If desired, click the arrow to the right of the Amplitude field, and select the amplitude of your choice from the list that appears. Alternatively, you can click to create a new amplitude. (See Chapter 57, “The Amplitude toolset,” for more information.)
If you are using the RNG k–
turbulence model in the current flow step, do the following
Toggle on Turbulent kinetic energy; and enter the turbulent kinetic energy, k, for the fluid.
If desired, click the arrow to the right of the Amplitude field, and select the amplitude of your choice from the list that appears. Alternatively, you can click to create a new amplitude. (See Chapter 57, “The Amplitude toolset,” for more information.)
Toggle on Dissipation rate; and enter the dissipation rate, , for the fluid.
If desired, click the arrow to the right of the Amplitude field, and select the amplitude of your choice from the list that appears. Alternatively, you can click to create a new amplitude.
Click OK to save your data and to exit the editor.
