Progress in Modeling 3D Shear Flows Using RANS Equations and Advanced Turbulence Models

This article reviews recent work in the area of advanced turbulence modeling for complex three-dimensional flows of engineering interest. The term “advanced” refers herein to models that resolve the near-wall flow and account for the anisotropy of the Reynolds stresses. Representative such models, including full Reynolds-stress transport and non-linear, two-equation models, that have already been successfully applied to complex flows are presented and their advantages and inherent limitations are discussed. Critical numerical issues that need to be addressed in order to facilitate the application of such models to complex flows are also examined. Emphasis is placed on high-resolution spatial discretization schemes and strongly coupled multigrid acceleration strategies for efficient and robust solution algorithms on stretched, large-aspect-ratio grids. Examples from applications of advanced turbulence models to three-dimensional flows are presented. The test cases considered include both internal and external flows with strong longitudinal vortices. Comparisons of the computed results with available experimental data point to the conclusion that quantitatively accurate predictions of complex shear flows require turbulence models that resolve the near-wall flow and account for turbulence anisotropy. The implications of these findings for future predictions of complex engineering flows are discussed. Progress in Modeling 3D ShearFlows, F. Sotiropoulos