Inflow
Use this node to model inflow of moisture through a virtual domain, at inlet boundaries of moist air domains. The upstream moisture conditions (either vapor concentration custr, or vapor mass fraction ωustr, or relative humidity and temperature Tustr) are known at the outer boundary of the virtual domain. The inflow condition is often similar to a moisture content condition. However using this condition the upstream vapor concentration is not strictly enforced at the inlet. The higher the flow rate, the smallest difference between the inlet and upstream moisture content. In case of moisture sources or moisture constraints close to the inlet boundary, the inflow condition induces a moisture profile that approaches to the moisture profile that would be obtained by computing the solution in the virtual domain upstream the inlet.
This boundary condition estimates the moisture flux through the inlet boundary from a Danckwerts condition on the concentration:
When the Concentrated species option is selected in the Mixture type for moist air list, this condition is rewritten as:
to be expressed in function of the mass fraction ωv, with
This node can be applied on the exterior boundaries of a computational domain in which a Moist Air (Moisture Transport Interface) node is active.
Upstream Properties
When Specify is set to Relative humidity in the Specify list, set both the Upstream temperature Tustr and the Upstream relative humidity from which the upstream vapor concentration can be defined:
For User Defined, enter values or expressions. Else, select any available input (like Ambient temperature defined in an Ambient Properties node under Definitions).
Alternatively, choose Vapor concentration in the Specify list, and set directly a value or expression for the Upstream vapor concentration custr.
Finally, choose Vapor mass fraction in the Specify list to set a value or expression for the Upstream vapor mass fraction ωustr.
Evaporative Cooling of Water: Application Library path Heat_Transfer_Module/Phase_Change/evaporative_cooling
Location in User Interface
Context Menus
Ribbon
Physics Tab with interface as Moisture Transport in Air, Moisture Transport in Building Materials, or Moisture Transport in Porous Media selected: