计算力学学报2023,Vol.40Issue(6):885-892,8.DOI:10.7511/jslx20220520002
适用于几何非线性气动弹性分析的结构动力学降阶模型方法研究
Study on structural dynamics reduced-order model for geometrically nonlinear aeroelastic analysis
摘要
Abstract
Geometric nonlinearity is one of the main characteristics of panel flutter and aeroelasticity of wings with high aspect ratios.In numerical analysis,commercial nonlinear finite element solvers are often required,which have many problems such as large computational workload and difficulties in control of coupled iterative strategy.In this paper,a reduced-order model of computational structural dynamics(ROM-CSD)for geometric nonlinearity is developed,the nonlinear internal forces are represented by nonlinear polynomials in generalized coordinates,polynomial coefficients are obtained by parameter identification method,and the prediction accuracy of the model is improved by adding additional linear modes.Based on this method,time-domain response analysis are carried out for the ROM-CFD/CSD nonlinear flutter problems of panel flutter and cropped delta wing flutter respectively.The results show that the flutter velocity and flutter frequency calculated by ROM-CSD are 590 m/s and 174 Hz,respectively,with the errors of 0.8%and 1.7%compared with the finite element results.When the Mach number is 0.879,the predicted flutter vibration pressure of the cropped delta wing is 2.25 psi,and the error is 3.8%compared with the nonlinear finite element method;The amplitude and frequency errors of limit cycle oscillation are within 11%in many working conditions.They show that the method presented in this paper has good computational accuracy and can replace nonlinear finite element method for aeroelastic analysis to some extent.关键词
几何非线性/降阶模型/非线性颤振/极限环振荡/气动弹性Key words
geometric nonlinearity/reduced order model/nonlinear flutter/limit cycle oscillation/aeroelas-ticity分类
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张兵,汪启航..适用于几何非线性气动弹性分析的结构动力学降阶模型方法研究[J].计算力学学报,2023,40(6):885-892,8.基金项目
国家自然科学基金(12172116)资助项目. (12172116)