4.5 Standard and SST $k$- $\omega$ Models

This section describes the theory behind the Standard and SST $k$- $\omega$ model. For details about using the models in ANSYS FLUENT, see this chapter and this section in the separate User's Guide.

This section presents the standard [ 379] and shear-stress transport (SST) [ 224] $k$- $\omega$ models. Both models have similar forms, with transport equations for $k$ and $\omega$. The major ways in which the SST model [ 225] differs from the standard model are as follows:

• gradual change from the standard $k$- $\omega$ model in the inner region of the boundary layer to a high-Reynolds-number version of the $k$- $\epsilon$ model in the outer part of the boundary layer

• modified turbulent viscosity formulation to account for the transport effects of the principal turbulent shear stress

The transport equations, methods of calculating turbulent viscosity, and methods of calculating model constants and other terms are presented separately for each model.