Outlet

The node adds a set of boundary conditions that describe outlets in fluid-flow simulations; that is, the conditions at boundaries where the fluid exits the domain.

Select a — (the default), , or .

The 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 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 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 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.

For click the (the default) or buttons.

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For specify that the velocity at the boundary is equal to a given u0 (SI unit: m/s) and enter the components in the matrix:

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For enter a value or expression for U0 (SI unit: m/s).

This boundary condition is applicable when the flow exits the domain into a long pipe or channel, at the end of which a flow profile is fully developed.

The boundary conditions for the virtual inlet channel are inherited from the boundaries adjacent to the outlet channel. Virtual boundaries adjacent to walls (except slip walls) are treated as no-slip walls. Virtual boundaries adjacent to any other type of boundary are treated as slip-walls (or equivalently as symmetry boundaries).

Select a — (the default), , or .

The settings for the are the same as for Wall. See Gas Boundary Condition.

When the is set to , the section contains an input field for the on the downstream side of the outlet. If is selected at the physics interface level, additional input fields appear for the or the on the downstream side of the outlet.