Defining a Mass Flow Inlet

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

See Also
About Inlets
Defining the Fluid Physics of a Flow Simulation
In Other Guides
Editing Simulation Features
  1. From the Boundaries section of the action bar, click Mass Flow Inlet .
  2. Optional: Customize the default Name of the inlet.
  3. Select the surface where fluid enters the domain.
  4. Select a mass flow specification from the Specification Type options:
    OptionDescription
    Mass Flow Rate Mass flow expressed in terms of mass over a specified period of time.
    Mass Flux A flow velocity vector that you define directly in terms of its X-, Y-, and Z-components in space.
  5. Describe the direction of mass flow from the Direction Specification options:
    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.
    Vector A flow velocity vector that you define directly in terms of its X-, Y-, and Z-components in space.

    For direct vector 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.
  6. Specify the Temperature of the fluid flowing into the inlet.

    If you want to apply a scale factor or amplitude to the temperature values, click , then specify either or both of the following:

    OptionDescription
    Scale factor A multiplier that is applied to the magnitude of the vector component in each step.
    Amplitude Name of the amplitude curve that defines the magnitude of the vector component during the step.
  7. Describe the turbulent flow at this inlet by selecting a Turbulence specification and customizing its settings. The following turbulence specifications are available:
    OptionDescription
    Viscosity ratio Define turbulence by specifying the eddy viscosity ratio.
    Intensity - Length scale Define turbulence by specifying the turbulence intensity, characteristic length scale, and velocity scale.
    Turbulent viscosity Define turbulence by specifying the kinematic eddy viscosity.

    The specific turbulence customization settings that appear depend on your 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.

  8. For compressible flow simulations, specify the Supersonic static gauge pressure of the fluid at the inlet. The solver applies this pressure value locally if the flow becomes supersonic.
  9. 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.
  10. 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
  11. If surface-to-surface radiation is active, you can specify the radiation behavior at the inlet. For more information, see Defining Surface-to-Surface Radiation Behavior at an Inlet.
  12. If particle physics are active, you can specify how the particles interact with the inlet. For more information, see Defining a Particle Boundary.
  13. Click OK.