A Three Equation Curvature and Rotation Sensitive Variant of the SST K-Omega Turbulence Model

To date, eddy viscosity models are the most accepted and widely used RANS-based turbulence closures, attributable to their computational efficiency and relative robustness. One notable shortcoming of these models is their insensitivity to system rotation and streamline curvature. In this article, we present a variation of the SST k-ω model properly sensitized to system rotation and streamline curvature. The new model is based on a direct simplification of the Reynolds Stress Model under weak equilibrium conditions. To enhance stability and include history effects, an additional transport equation for a transverse turbulent velocity scale is added to the model. The new transport equation incorporates the physical effect of curvature and rotation on the turbulence structure. The eddy viscosity is then redefined based on the new turbulent velocity scale. The model is calibrated based on rotating homogeneous shear flow and implemented for a number of test cases including rotating channel, U-duct, and hump model flow. Compared to popular two equation models, the new model shows improved performance in system rotation and/or streamline curvature dominated flows.