Reaction Sources
Use the Reaction Sources node to define mass source terms from one or more chemical reactions. Both homogeneous reactions as well as heterogeneous reactions occurring in a porous media can be studied. The node also includes the possibility to pick up automatically defined source term definitions from a Chemistry interface.
Reactions
The combo box Chemistry lists all the Chemistry interfaces that are coupled to the current mass transport interface. The coupled chemistry interface should
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 Be active
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Not have Define variables for porous pellets (under the Pellet Chemistry section) selected
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Have Species solved for (under the Species Matching section) set to the current mass transport interface.
Furthermore
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With a Chemistry interface selected, the species mass sources will be set to the corresponding reaction rates in Chemistry according to the Species Matching table. In the case of partial coupling, the mass sources for the uncoupled species will be set to 0.
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With User defined selected, specify mass source (SI unit: kg/(m3·s)) for each species, or pick up a reaction rate variable from a Chemistry interface.
Select the Mass transport to other phases checkbox if mass is leaving or entering the fluid as a result of the reactions, for instance due to condensation or vaporization in a porous matrix. In this case the mass source for the species calculated from the mass constraint can also be specified. The net mass transfer corresponds to the sum of the mass sources for all species.
Reacting Volume
This section is available when the Chemistry list is set to User defined.
When specifying reaction sources for a species in porous media, the specified mass source may have the basis of the total volume, or the pore volume. For nonporous domains, the Reacting Volume setting has no impact.
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For Total volume, the reaction mass source expressions are specified per unit volume of the model domain.
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For Pore volume, the reaction mass source expressions are specified per unit volume pore space. In this case the reaction mass sources will be multiplied by the domain porosity εp (εp equals unity for nonporous domains).
When a coupled chemistry is selected from the Chemistry list, the porosity will be applied to the reaction source terms automatically.
Heat Source
The heat source will be defined as reaction heat from whole Chemistry if the Chemistry list is set to a coupled chemistry interface, otherwise it is defined as the specified value (entered by the user).