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.

中文翻译：

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基于汽车周围流动的低雷诺数湍流模型改进研究

摘要 本文为稳态和瞬态解决方案提出了两种新的湍流模型。对于稳态解，通过在低雷诺数（LRN）k-ε模型中引入流线曲率因子和响应阈值，得到改进的LRN k-ε模型，用于模拟汽车流场通过 Fluent 求解器。修正模型、realizable k-ε模型、原始LRN k-ε模型和HD-2风洞试验结果对比表明，修正模型最能模拟气流分离、尾流流场、气动力。准确。对于瞬态求解，通过结合约束大涡模拟（CLES）思想和修正模型方法对RANS/LES模型进行修正，提出了一种过渡LRN CLES模型。过渡模型的比较，