A.1 Description

You need to use DEFINE_HET_RXN_RATE to specify reaction rates for heterogeneous reactions. A heterogeneous reaction is one that involves reactants and products from more than one phase. Unlike DEFINE_VR_RATE, a DEFINE_HET_RXN_RATE UDF can be specified differently for different heterogeneous reactions.

During ANSYS FLUENT execution, the DEFINE_HET_RXN_RATE UDF for each heterogeneous reaction that is defined is called in every fluid cell. ANSYS FLUENT will use the reaction rate specified by the UDF to compute production/destruction of the species participating in the reaction, as well as heat and momentum transfer across phases due to the reaction.

A heterogeneous reaction is typically used to define reactions involving species of different phases. The bulk phase can participate in the reaction if the phase does not have any species (i.e. phase has fluid material instead of mixture material). Heterogeneous reactions are defined in the Phase Interaction dialog box.