The turbulence model is based on a standard k-e model, with buoyancy extension, see e.g. Rodi (1980). This model uses transport equations for the turbulent kinetic energy (TKE), k, and the dissipation of TKE, e, to describe the turbulence.
In the k-e closure model, the Prandtl number, which appears in the transport equations for k and e, can be modified explicitly following the empirical expression of Munk and Anderson (1948). This correction will introduce a damping of the buoyancy production in case of stable stratification. This damping is included by default.
Empirical constants
Maximum and minimum values