Outflow
This node provides a boundary condition at outlets where the vapor is transported out of the air domain. It is assumed that convection is the dominating transport mechanism across outflow boundaries, and therefore that diffusive transport can be ignored. For boundaries of a moist air domain, it gives:
For boundaries of a porous medium, the sum of vapor diffusive flux and liquid capillary flux is nullified:
This node can be applied on the exterior boundaries of a computational domain in which either a Moist Air (Moisture Transport Interface) node, a Hygroscopic Porous Medium node with Equilibrium between liquid and gas phases set to Equilibrium formulation, or a Moist Air (Hygroscopic Porous Medium) subnode when it belongs to a Hygroscopic Porous Medium node with Equilibrium between liquid and gas phases set to Nonequilibrium formulation is active. In the latter case, this node only constrains the vapor flux.
Location in User Interface
Context Menus
Moisture Transport in Air > Flow Conditions > Outflow
Moisture Transport in Building Materials > Flow Conditions > Outflow
Equilibrium Moisture Transport in Porous Media > Flow Conditions > Outflow
Nonequilibrium Moisture Transport in Porous Media > Flow Conditions > Outflow
Nonequilibrium Moisture Transport in Porous Media > Hygroscopic Porous Medium > Moist Air > Flow Conditions > Outflow
Ribbon
Physics tab with interface as Moisture Transport in Air, or any version of the Moisture Transport interface selected:
Boundaries > interface > Outflow
Physics tab with Hygroscopic Porous Medium > Moist Air selected in the model tree:
Attributes > Outflow