Define Atmospheric Inlets

Use the Atmospheric tool to define atmospheric boundary layers at an inlet.

When the inflow type is set to atmospheric, the inlet velocity profile and turbulence inflow quantities are generated automatically. Inlet velocity is prescribed via log law while inlet turbulence properties are computed according to the chosen turbulence model. Necessary inputs are surface roughness and reference velocity.

Corresponding velocity and turbulence boundary conditions at the inflow will be generated automatically. Note that there should be an empirical ratio (30) between inflow roughness and standard wall roughness. For example, if atmospheric boundary layer inflow has a roughness of 0.001m on the ground, the standard turbulence wall function should have a roughness of 0.03m.

  1. From the Flow ribbon, click the Atmospheric tool.

    Figure 1.
  2. Select inlet surfaces.
  3. Using the widget in the modeling window as reference, define the flow direction (green arrow), ground normal (red arrow), and origin (position of the widget).
    • Click in the microdialog to align and position the widget using the Move tool. After moving, press Esc to return to the current tool.
    • Click in the microdialog to orient the plane using the Vector tool. Once the orientation has been defined, press Esc to return to the current tool.
  4. Define the ground roughness and reference velocity in the microdialog.
  5. Optional: Click the Setting tab and update the precedence value.
  6. From the guide bar, execute the command in the following ways:
    • Click to confirm your selection and remain in the tool.

      This allows you to continue creating instances and helps you visualize and edit instances with the legend.

    • Click to confirm your selection and exit the tool.