## 7.5. The Finite Rate Chemistry Model

The Finite Rate Chemistry model, as implemented in CFX, assumes that the rate of progress of elementary reaction k can be reversible only if a backward reaction is defined. Therefore, the rate of progress R k, is computed as:

| (7–11)

where [ I ] is the molar concentration of component I and F k and B k are the forward and backward rate constants respectively.

r represent the reaction order of component I in the elementary reaction k. This reaction order is equal to the stoichiometric coefficient for elementary reactions, but it can be different for certain global reactions.

The only built-in formula for the forward and backward rate constants assumes an Arrhenius temperature dependence as:

| (7–12)

| (7–13)

where:

- A k is pre-exponential factor

- is the temperature exponent (dimensionless)

- E k is the activation energy

- T is the absolute temperature

can also be specified directly without using relations.

Separate sets of coefficients , and are applied to forward and backward rates.

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