Outlet
The Outlet node adds a selection of boundary conditions that describe outlets in fluid-flow simulations; that is, the conditions at boundaries where the fluid exits the domain.
Mixture Boundary Condition
Select a Mixture boundary condition for the outlet — Pressure (the default) or Velocity.
Pressure Conditions
The Pressure condition specifies the normal stress which in most cases is approximately equal to the pressure. The tangential stress component is set to 0 N/m2.
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Enter the Pressure p0 (SI unit: Pa) at the boundary. The default is 0 Pa. Enter a relative pressure value in p0 (SI unit: Pa). Or if the reference pressure pref defined at the physics interface level is equal to 0 Pa, enter an absolute pressure in p0.
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Select the Normal flow check box to change the no tangential stress condition to a no tangential velocity condition. This forces the flow to exit (or enter) the domain perpendicularly to the outlet boundary.
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The Suppress backflow check box is selected by default. This option adjusts the outlet pressure in order to reduce the amount of fluid entering the domain through the boundary.
Velocity
For Velocity click the Normal outflow velocity (the default) or Velocity field buttons.
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For Normal outflow velocity enter a value or expression for J0 (SI unit: m/s).
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For Velocity field specify that the velocity at the boundary is equal to a given j0 (SI unit: m/s) and enter the components in the matrix:
Dispersed Phase Boundary Condition
The default is Dispersed phase outlet. See Wall>Dispersed Phase Boundary Condition for the settings.
When the Dispersed phase boundary condition is set to Dispersed phase outlet, the Exterior dispersed phase condition(s) section contains an input field for the Dispersed phase volume fraction on the downstream side of the outlet. If Solve for interfacial area is selected at the physics interface level, additional input fields appear for the Dispersed phase number density or the Diameter of particles/droplets on the downstream side of the outlet.
See Dispersed Phase Boundary Condition Equations for more information.
See Outlet in the Single-Phase Flow interfaces