摘要
建立了求解弹性机翼阵风响应的计算方法。在计算中,通过采用数值方法求解三维非定常Euler方程来获得气动特性;采用模态叠加的方法考虑弹性影响,实现了流体力学和弹性力学的耦合计算。通过对刚性机翼在攻角突然增大的阵风作用下的响应历程计算和二维NLR7301翼型的极限环振荡计算,对计算方法进行了验证。此后在"1-cos"阵风响应的计算中考虑弹性效应影响,先是只考虑了结构变形的前三个基本模态,弹性机翼气动力响应的计算结果与刚性机翼的响应计算结果有比较大的区别,弹性机翼阵风响应的升力峰值低于刚性机翼,这与文献中的结果是一致的。最后在计算中考虑了高阶弹性模态,计算结果表明:考虑高阶模态后,机翼气动力计算结果的总体变化趋势与只考虑前三个模态时基本一致,但结果中出现了高频的波动,波动的频率与高阶模态本身的频率有关。
The numerical method to calculate the gust response of elastic wing was developed in this paper. In this numerical method, the aerodynamic forces of the rectangular wing with aspect ratio of 5 were calculated by solving the unsteady Euler equations, the elastic effect was considered with Ray leigh--Ritz method, so that the fluid dynamic and structural dynamic problems can be coupled to solve. In order to validate the feasibility of this numerical method, the case of gust leading a step change of the rigid wing＇s incidence and the case of Limiting Cycle Oscillation calculation of NLR7301 airfoil were investigated. The calculated results of these cases agreed with those presented in references and therefore verified the effectiveness of the numerical method. Furthermore, the elastic effect was taken in account, and at first only the first three fundamental elastic modes were used to calculate the wing＇s response of ＂1-cos＂ gust. It can be seen from the result that the peak value of lift response calculated by elastic wing was lower than that calculated with rigid wing, which agreed with the result in the reference. Finally, a high-order elastic mode was employed in the calculation and the results revealed that there was an agreement between the trends of the calculated curves of aerodynamic forces and those calculated only involving the first three fundamental elastic modes. However, there were some high-frequency oscillations in the aerodynamic forces due to the employment of high-order elastic mode and the oscillation frequency should be consistent with the natural frequency of the high-order elastic mode.
出处
《计算力学学报》
EI
CAS
CSCD
北大核心
2009年第2期270-275,共6页
Chinese Journal of Computational Mechanics
关键词
弹性机翼
阵风响应
模态叠加法
elastic wing
gust response
Rayleigh-Ritz method
