Study of 𝝎-Based Reynolds Stress Model with Two-Component Limit for Predicting Complex Flows

The turbulence flow and boundary layer transition occurring in turbomachinery pose significant challenges in accurately predicting aerodynamic characteristics by the Reynolds-Averaged Navier-Stokes approach. The Reynolds stress model (RSM) operates at the second-moment level, providing potential improvements in predicting strong anisotropy and non-equilibrium turbulence. In this study, a new specific dissipation rate 𝜔-based RSM is developed, inspired by the Speziale-Sarkar-Gatski/Launder-Reece-Rodi (SSG/LRR-𝜔) RSM, which is widely used in the aviation industry. Utilizing a new blending function, a transition between the pressure-strain terms proposed by Launder, Reece, and Rodi (1975), and those incorporating the two-component limit (TCL) proposed by Fu et al. (1987) is implemented from the near-wall to the mainstream regions, resulting in the TCL/LRR-𝜔 model. The newly devised blending function shares similarities with the one in the shear stress transport (SST) 𝑘-𝜔 model, but with an enhanced sensitivity to the effect of the three-dimensional (3D) vortex stretching. In addition, the Yap correction is introduced to address the unphysical backbending of the streamlines near the reattachment point. Validation conducted across the zero-pressure gradient flat plate and NASA hump indicates comparable predictive accuracy in characterizing the mean flow and superior predictive accuracy in the separation flows when compared to the shear stress transport (SST) 𝑘-𝜔 and SSG/LRR-𝜔 models. Furthermore, the blending of the TCL/LRR-𝜔 model with the intermittency 𝛾 transition model proposed by Menter et al. (2015) is investigated based on the NACA65 K48 compressor cascade, suggesting promising potential for further development.