结合机器学习的SA湍流模型闭合系数修正  

Closure coefficient modification of SA turbulence model combined with machine learning

作　　者：徐向阳 胡冠男[2] 王良军 朱文浩[2,3] 张武 XU Xiangyang;HU Guannan;WANG Liangjun;ZHU Wenhao;ZHANG Wu(School of Mechanics and Engineering Science,Shanghai University,Shanghai 200444,China;School of Computer Engineering and Science,Shanghai University,Shanghai 200444,China;Information Technology Office,Shanghai University,Shanghai 200444,China)

机构地区：[1]上海大学力学与工程科学学院,上海200444 [2]上海大学计算机工程与科学学院,上海200444 [3]上海大学信息化工作办公室,上海200444

出　　处：《上海大学学报（自然科学版）》2024年第2期341-351,共11页Journal of Shanghai University:Natural Science Edition

基　　金：国家自然科学基金重大研究计划重点资助项目(91630206)。

摘　　要：将修正Morris分类筛选法与极端梯度提升(extreme gradient boosting,XGBoost)相结合,在计算流体动力学(computational fluid dynamics,CFD)数据驱动下,用于SA(Spalart-Allmaras)湍流模型闭合系数的修正.利用分类筛选法有效缩小闭合系数研究范围,同时依据XGBoost方法在小规模数据集下取得精度较高的拟合模型,有效提升系数修正效率.在三维DLR-F6-WB构型下进行了数值实验,实验结果显示利用本方法能够在三维复杂模型上基于小样本数据进行系数修正,修正后的升阻力系数计算精度得到了显著提升.This paper presents a combined approach integrating the modified Morris classification and screening method with extreme gradient boosting(XGBoost),driven by computational fluid dynamics(CFD)data.The methodology is applied to modify the closure coefficient of the Spalart-Allmaras(SA)turbulence model.The utilization of the classification and screening method effectively narrows the research scope of the closure coefficient.Using the XGBoost method,a highly accurate fitting model can be obtained even with a small-scale data set,leading to effective improvements in the efficiency of coefficient modification.Employing this method,numerical experiments are conducted for the flow over the three-dimensional(3D)DLR-F6-WB configuration.The experimental results demonstrate the method’s capability to rectify coefficients on complex 3D models based on small sample data.Consequently,the accuracy of the modified lift-drag coefficients has been significantly improved.

关 键 词：SA(Spalart-Allmaras)湍流模型 敏感度 极端梯度提升(extreme gradient boosting XGBoost) 线性回归 系数修正 

分 类 号：O35[理学—流体力学] TP181[理学—力学]