Openings
Openings, also called vents, are pressure and temperature specified boundaries. The boundary condition imposed depends on the direction of the flow: inflow or an outflow. The direction of the flow at a vent can vary during the solve.
The flow solver uses the node-based treatment, which means that the control volume around
each node of a vent can have incoming or outgoing flow separately from its neighbors.
For separated or reversed flow at an opening, you can activate the faceset-based
treatment for openings by using the USE FACESET-BASED TREATMENT FOR
OPENINGS
advanced parameter. The direction of the total mass flow through
the opening faceset is used to determine if the flow is coming in or going out of the
domain for all elements of the opening.