李文成，金栋平
摘要:建立了基于 Kriging 代理和递归算法的变厚度翼型气动力降阶模型，将滤波的高斯白噪声作为输入信号，采用计算流体力学(CFD)方法获得不同厚度下翼型的非定常气动力并将其作为降阶模型的训练样本。该降阶模型不仅大大提高了非定常气动力的计算效率，而且其预测得到的非定常响应的精度不低于 92.01%。通过蒙特卡洛法的变厚度翼型全局灵敏度分析表明，俯仰运动是影响气动力波动的主要因素，俯仰与沉浮位移的耦合对气动力影响很小。考虑翼型变厚度时对翼面压力及分离点的影响，本文建立了压强系数的降阶模型。通过与 CFD 结果的对比，得到其精度为 99.9995%，验证了降阶模型的正确性和有效性。
关键词：变翼型; 非定常气动力; 模型降阶; Kriging代理; 蒙特卡洛法
Reduced-order model for unsteady aerodynamic forces of a variable thickness airfoil and influence analysis
Wencheng Li, Dongping Jin
Abstract：A Reduced-order Model(ROM) for unsteady aerodynamic forces of a variable thickness airfoil has been developed based on the Kriging surrogate model and a recursive algorithm, which uses the training samples of the unsteady aerodynamic forces of different airfoils obtained by Computational Fluid Dynamics(CFD) with the filtered white Gaussian noise as input signals. The calculation efficiency for unsteady response could be improved significantly by ROM, with accuracy is not less than 92.01%. Monte-Carlo simulations are used to analyze the global sensitivity based on the reduced order model. Results obtained show that the pitching motion of the airfoil plays a key role in the aerodynamic forces, compared with the coupling factors of the pitch and plunge motions. In addition, the ROM for pressure coefficients is also obtained, with consideration of the effect of airfoil variable thickness on pressure coefficients and separation locations. The accuracy and validity of ROM are verified through CFD, and the accuracy could reach 99.9995%.
Keyword：variable airfoil, unsteady aerodynamic force, reduced-order model, Kriging surrogate, Monte-Carlo method.
原文链接：http://www.cjam.xjtu.edu.cn/oa/DArticle.aspx?type=view&id=20180220
