With the Reynolds stress model in Ansys Fluent, turbulent heat transport is modeled using the concept of Reynolds’ analogy to turbulent momentum transfer. The "modeled" energy equation is therefore given by the following:

(4–262)

where is the total energy and is the deviatoric stress tensor, defined as

The term involving represents the viscous heating, and is always computed in the density-based solvers. It is not computed by default in the pressure-based solver, but it can be enabled in the Viscous Model Dialog Box. The default value of the turbulent Prandtl number is 0.85. You can change the value of in the Viscous Model Dialog Box.

Turbulent mass transfer is treated similarly, with a default turbulent Schmidt number of 0.7. This default value can be changed in the Viscous Model Dialog Box.