Defining a Velocity Inlet

You can specify the magnitude and direction of fluid flow at the opening where the flow enters the fluid domain.

See Also
Defining the Fluid Physics of a Flow Simulation
In Other Guides
Editing Simulation Features
Defining a Fluid Domain
  1. From the Flow section of the action bar, click Velocity Inlet .
  2. Optional: Enter a descriptive Name.
  3. Select the surface where fluid enters the domain.
  4. From the Direction specification options, select a vector type:
    OptionDescription
    Normal An inlet vector that is normal to the selected surface at all points on the surface. When you choose this option, you must also specify the Magnitude of the normal vector.
    Cartesian Vector A flow velocity vector that you define directly in terms of its X-, Y-, and Z-components in Cartesian axis system.
    Cylindrical Vector A flow velocity vector that you define directly in terms of its radial (R), tangential (T), and axial (Z) components in a cylindrical axis system.

    For Cartesian or cylindrical definition, you can also specify the Axis system definition to align the inlet vector with a different axis system.

    OptionDescription
    Global The global axis system.
    Local A local axis system specified as a component of the part definition. You can select the triad for the local axis system by clicking it in the 3D area. If no local axis system is available, you must define one in a part definition app.
    Specify Orient the inlet vector directly by right-clicking the feature triad glyph on the model and selecting an orientation tool.
  5. Specify the Velocity and Temperature of the fluid entering the fluid domain.

    For either parameter, you can use a single uniform value, spatially varying mapped data, or JavaScript user subroutines that define the value programmatically.

    In addition, you can apply a scale factor or amplitude to the value. Click , then specify either or both of the following:

    OptionDescription
    Scale factor A multiplier that is applied to the magnitude of the value in the step.
    Amplitude Name of the amplitude curve that defines the magnitude of the value during the step.
  6. Describe the turbulent flow at this inlet by selecting a Turbulence specification and customizing its settings.

    The specific turbulence customization settings that appear depend on your specification choice and on the turbulence model you chose in the physics definition. For a full description of all available turbulence settings, see Initial Turbulence Options.

  7. For multispecies flow analyses, you can also specify the mass fraction of the materials flowing through the inlet. For more information, see Defining Mass Fractions at an Inlet.
  8. For a multiphase simulation using the Volume of Fluid (VOF) method, you can also specify the material distribution flowing through the inlet. In addition, gravity waves can be specified as part of the material distribution. For more information, see Defining Volume Fractions at an Inlet
  9. If surface-to-surface radiation is enabled in the fluid physics, you can specify the radiation behavior at the inlet. For more information, see Defining Surface-to-Surface Radiation Behavior at an Inlet.
  10. If particle physics are active, you can specify how the particles interact with the inlet. For more information, see Defining a Particle Boundary.
  11. Click OK.