Sensitization of a Transition-Sensitive Linear Eddy-Viscosity Model to Rotation and Curvature Effects

Abstract

A new scalar eddy-viscosity turbulence model is proposed, designed to exhibit physically correct responses to flow transition, streamline curvature, and system rotation effects. The eddy-viscosity model (EVM) developed herein is based on the k–ω framework and employs four transport equations. The transport equation for a structural variable (v2) from a curvature-sensitive Shear Stress Transport (SST) k–ω–v2 model, analogous to the transverse turbulent velocity scale, is added to the three-equation transition-sensitive k–kL–ω model. The physical effects of rotation and curvature (RC) enter the model through the added transport equation. The new model is implemented into a commercial computational fluid dynamics (CFD) solver and is tested on a number of flow problems involving flow transition and streamline curvature effects. The results obtained from the test cases presented here are compared with available experimental data and several other Reynolds-Averaged Navier-Stokes (RANS) based turbulence models. For the cases tested, the new model successfully resolves both flow transition and streamline curvature effects with reasonable engineering accuracy, for only a small increase in computational cost. The results suggest that the model has potential as a practical tool for the prediction of flow transition and curvature effects over blunt bodies.

Improvement of the SST γ-Reθt transition model for flows along a curved hydrofoil

“…In a turbomachinery, the streamline curvature caused by the curved walls or by the rotation of the flow field will affect the generation of the turbulent kinetic energy and the boundary layer transition. The curvature of the streamlines is not considered in the traditional eddy viscosity model [16][17] , so it is necessary to consider the curvature effect in the application of this model. In some studies [18][19] , the influence of the rotation and the streamline curvature were considered by adding generating terms in the SST turbulent kinetic energy transport equation to be coupled with the SSTt Re   transition model.…”