If this node is selected from the Pairs menu, choose the pair on which to apply this condition. A pair has to be created first. See
Identity and Contact Pairs in the
COMSOL Multiphysics Reference Manual for more details.
When Specify is set to
Relative humidity, the equation for this condition is
where and
T0 are the prescribed relative humidity and temperature on the boundary. For
User Defined, enter values or expressions. Else, select any available input (like
Ambient temperature defined in an
Ambient Properties node under
Definitions). If the
Concentrated species formulation is used, the vapor mass fraction is then defined as:
Alternatively, choose Vapor concentration in the
Specify list and set directly the
Vapor concentration c0. If the
Concentrated species formulation is used, the vapor mass fraction is then defined as:
Finally, choose Vapor mass fraction in the
Specify list to set directly
ω0. If the
Diluted species formulation is used, the vapor concentration is then defined as:
To display this section, click the Show More Options button (
) and select
Advanced Physics Options. Select the
Use weak constraints check box to replace the standard constraints with a weak implementation.
The Discontinuous Galerkin constraints option ensures continuity of the diffusive flux.