Research on improvements of low Reynolds number turbulence model based on flow around automobiles

Abstract

This article proposes two new turbulence models for steady-state and transient-state solutions. For the steady-state solution, by introducing the streamline curvature factor and response threshold value into the low Reynolds number (LRN) k-ε model, a modified LRN k-ε model is obtained, which is applied to simulate an automobile flow-field by Fluent solver. The comparisons among the results obtained by the modified model, realizable k-ε model, original LRN k-ε model, and HD-2 wind tunnel test show the modified model can simulate the flow separation, the wake flow-field, aerodynamic force most accurately. For the transient-state solution, by combining the constrained-large-eddy simulation (CLES) idea with the modified model method to modify the RANS/LES model, a transition LRN CLES model is proposed. The comparisons of the transition model, scale-adaptive simulation (SAS) model, and the actual road test results for aerodynamic noise show that the transition LRN CLES model has the better simulation ability.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work is supported by National Natural Science Foundation of China [Grant Nos. 51975197, 51875186] and The Science and Technology Innovation Plan of Hunan Province, China [Grant No. 2017TD2522].