The Chemistry Postprocessing model calculates material components and reactions one-way coupled to the main simulation. This is appropriate when the component mass fractions and the reaction rates are sufficiently small so that their effect on mixture properties and flow field may be neglected. This is the case for tracer materials or pollutants and their corresponding formation and destruction reactions (for example, the NO model).

Solving materials with postprocessing has the advantage that the corresponding transport equations are solved under the final flow and temperature fields from the beginning and, therefore, fewer iterations are required before convergence is reached. Further, postprocessing allows for running different variations of the pollutant formation models based on the same (frozen) main solution.

The following topics will be discussed: