Assessment of nonlinear-low Reynolds number/detached eddy simulation turbulence model for wake flow field simulation of a realistic automotive model

Abstract

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.

A Computational Method for Complex-shaped Hydraulic Turbomachinery Flow Based on Immersed Boundary Method

“…Under the design advance coefficient J = 0.833, the influence of the free surface on the qualitative distribution characteristics of the propeller wake is relatively small, and the macroscopic wake is consistent with that of the open water condition. We have discussed this aspect in more specific in other studies, and more details can be found in the Reference [37]. Therefore, we will not repeat the discussion of velocity and pressure characteristics under flat inflow and wave conditions.…”