Setting Up Inlets and Outlets

Define fluid flowing into or out of the model at a specified location.
  1. Click the Fluid Flow dropdown menu in the Simulation tab ribbon and choose Flow.
  2. Select one or more faces to apply a flow condition.
    If your model contains named selections, click Advanced filters and use Link named selections to choose one from the list.
  3. In the Fluid Flow HUD, specify the direction of flow to be in or out by selecting Inlet or Outlet.
  4. Set the fluid flow condition type to be a velocity, mass flow rate, or pressure inlet or outlet.

    • For Velocity, enter the velocity magnitude at which fluid is flowing into or out of the domain.

      If the fluid flow into the domain has rotating or twisting movement as it enters an flow inlet, select Swirling flow and specify the speed of fluid rotation. You can reverse the direction of rotation by entering a negative rotational speed or double-clicking the arrow showing the rotation direction.

    • For Mass flow rate, this is where fluid is delivered by a positive displacement device upstream and is capable of overcoming the back pressure of the system being modeled.
    • For Pressure, enter the gauge total pressure, which represents the pressure obtained by bringing the flow isentropically to rest (for example, upstream plenum pressure). It is measured relative to the operating pressure.
    Note: Your setup must make sense from a physics perspective. So, for example, you can’t specify 10kg of fluid flowing into your model and only 2 kg leaving. For this reason, it is highly recommended that one of your flow conditions is defined by pressure.
  5. To include the distribution of temperature within the fluid, you will need to specify the in-flow Temperature and the backflow temperature where applicable. You will specify the total temperature (also known as the stagnation temperature) rather than the static temperature. The total temperature represents the temperature of the fluid in a plenum at rest upstream. The local static temperature will be lower, depending on the velocity of the fluid.