The Pressure Point Constraint condition can be used to specify the pressure level. If it is not possible to specify the pressure level using a boundary condition, the pressure level must be set in some other way, for example, by specifying a fixed pressure at a point.
The relative pressure value is set by specifying the Pressure p0. Or, if the reference pressure
pref defined at the physics interface level is equal to zero,
p0 represents the absolute pressure.
) and selecting Advanced Physics Options.