Gao-Yong湍流模型对边界层转捩的适用性研究  

The applicability study of Gao-Yong turbulence model to boundary layer transitions

作　　者：孙逸凡 朱炜 吴玉新[1] 祁海鹰[1] SUN Yifan;ZHU Wei;WU Yuxin;QI Haiying(Department of Energy and Power Engineering,Tsinghua University,Beijing 100084,China)

机构地区：[1]清华大学能源与动力工程系,北京100084

出　　处：《清华大学学报（自然科学版）》2023年第4期642-648,共7页Journal of Tsinghua University(Science and Technology)

基　　金：国家科技重大专项(Y2019-I-0022-0021)。

摘　　要：准确预测边界层转捩对深入理解湍流边界层发展和飞行器翼型优化工业应用等具有重要意义。为提升Gao-Yong(G-Y)湍流模型对平板边界层发展及转捩特性预测的准确性与适用性,该文提出了采用G-Y漂移位矢Reynolds数(ReT)表征当地湍流脉动强度的方法,建立实度系数(Cs)与ReT间的函数关系,解决G-Y湍流模型中Cs取值间断、分布离散的问题。基于开源OpenFOAM软件开发了改进G-Y湍流模型的求解器,对经典平板边界层和转捩实验开展计算流体力学(computational fluid dynamics,CFD)数值模拟并验证。研究结果表明,相比k-ω等传统雷诺平均(Reynolds averaged Naviers-Stokes,RANS)模型,改进后的G-Y湍流模型不仅能准确模拟边界层流动特征,还能合理预测边界层发展过程及转捩位置,准确性较高。结果表明,经过改进的G-Y湍流模型可进一步用于对边界层转捩特性的研究。[Objective]Transition is one of the most significant progressions in fluid mechanics.Accurate boundary layer transition prediction is also essential for a complete understanding of the production of turbulent boundary layers and the optimization of airfoil shapes for industrial applications.Turning turbulence models can accurately forecast transition by including an empirical turning criterion,a low Reynolds number viscous flow field characteristic,or an intermittency component for flow in the transition zone.As for the conventional turbulence models using Reynolds averaging method,such as the k-εand the k-ωmodels,accurately forecasting this phenomenon is tough since the transition process is poorly characterized or described.[Methods]A functional correction relation for the G-Y model is suggested and put to the test in the calculations to increase its precision and usefulness for forecasting boundary layer development and transitional features across flat plates.The coefficient of substance Cs had the problem of discontinuous distribution and intermittent values in the original model.This work provided a correlation formula between Cs and the drift vector Reynolds number ReT to solve this problem.The drift vector Reynolds number ReT is built using the G-Y model's drift velocity and vector to describe the strength of local turbulent pulsations.With the aid of physical understanding,the Cs-ReT relationship is produced,resulting in a continuous distribution of the real degree coefficient with ReT variation,close to 0 at the location of mild turbulent pulsation and close to 2/3 at the location of strong turbulent pulsation.The turbulent viscosity is bound by the size of the real degree coefficient at the point of weak turbulent pulsation by solving the discrete distribution's initial problem in this manner.[Results]A solver for the modified G-Y turbulence model was made using the open-source program OpenFOAM.The CFD numerical simulations and validation were then performed for the tests involving the T3A and T3B tr

关 键 词：数值模拟 G-Y湍流模型 平板边界层 转捩 

分 类 号：O357.4[理学—流体力学]