The composition PDF transport model, like the Laminar Finite-Rate (see Direct Use of Finite-Rate Kinetics (no TCI)) and EDC model (see The Eddy-Dissipation-Concept (EDC) Model), should be used when you are interested in simulating finite-rate chemical kinetic effects in turbulent reacting flows. With an appropriate chemical mechanism, kinetically-controlled species such as CO and NOx, as well as flame extinction and ignition, can be predicted. PDF transport simulations are computationally expensive, and it is recommended that you start your modeling with small meshes, and preferably in 2D.

Ansys Fluent has two different discretizations of the composition PDF transport equation, namely Lagrangian and Eulerian. The Lagrangian method is strictly more accurate than the Eulerian method, but requires significantly longer run time to converge.

For limitations that exist with the composition PDF transport mode in Ansys Fluent, see Limitation in the Fluent User's Guide.