k-kL两方程湍流模型的改进及验证研究

提高湍流数值模拟的准确性,从而明确湍流模型对数值模拟结果的影响具有重要的意义,应用K.S.Abdol-Hamid给出的尺度自适应k-kL两方程模型封闭RANS方程,并修改von Karman长度尺度的限制方法,通过平板、翼型、后台阶等流动的模拟,考察k-kL模型在湍流模拟中的准确性,及其反映主要流动特征的能力和网格收敛性,并对影响流动模拟准确性的因素进行讨论.结果表明:改进长度尺度限制之后的k-kL两方程模型无论是对附着流动还是分离流动都可以给出比较准确的结果.

Improvement and Validation of k-kL Two-Equation Turbulence Model

In order to improve the accuracy of turbulence flow simulations, the k-kL two-equation turbulence model constructed by Abdol-Hamid is applied to close RANS equations and assessed. In this paper, a modification to the upper limit in von Karman length scale is proposed. Some factors effecting simulation accuracy are also discussed. A number of test cases including flat plate case, airfoil case and backward facing step case are run to demonstrate the accuracy of this model, its capability to resolve important flow features and grid convergence. Test results show that this turbulence model is superior or at least comparable to other two-equation turbulence models in simulating either attached or separated turbulent flows.