Assessment of Nonlinear-Low Reynolds Number/Detached Eddy Simulation Turbulence Model for Wake Flow Field Simulation of a Realistic Automotive Model

Since the results of wake flow simulation with commonly used turbulence models are unsatisfactory, by introducing a nonlinear Reynolds stress term and combining the DES (Detached Eddy Simulation) model, this paper further validates the nonlinear-LRN (Low Reynolds Number)/DES turbulence model which can predict flow separation and reattachment phenomenon more accurately. This model was verified by a wall-mounted hump flow case and was applied to the time-averaged and transient flow field structure analysis of a realistic automotive model with several widely used turbulence models. These simulation results were compared with the experimental data, indicating that nonlinear-LRN/DES model gives better agreements with the experiment and can predict the automobile wake flow structures and aerodynamic characteristics more accurately. Furthermore, the performance of the nonlinear-LRN/DES model in mesh with different refinement are compared, concluding that the new proposed model can obtain high accuracy in coarse mesh.