The Reactions subnode to the Reactive Pellet Bed is used to define reaction terms to the transport within the reactive pellets. The feature also defines the corresponding averaged heat sources to be applied to heat transport in the bulk fluid.

From the Selection list, choose the domains on which to define rate expression or expressions that govern source terms in the transport equations.

Select a reaction rate (SI unit: mol/(m3·s)) for species i from Rpe,i list. Enter a reaction rate expression when User defined is selected from the list. Alternatively, if reaction rate expressions have been defined in a Chemistry interface, they can be chosen from the list.

When specifying reaction rates for a species in the pellet, the specified reaction rate may have the basis of the pore volume, or the total volume. With the Pore volume selected, the reaction expression in mol/(m3·s) will be multiplied by pellet’s porosity εpe.

The section is available when one or more surface species have been added in the Surface Species section of the Reactive Pellet Bed feature.

Specify the rate expression Rsurf,i (SI unit: mol/(m2·s)) corresponding to the surface reaction rate of each volumetric species i participating in the surface reaction. Furthermore, specify the surface reaction rates for the participating surface species in the corresponding table.