Aeroelastic analysis at high angles of attack is an attractive and complicated research subject in modern aircraft design. By using the Navier-Stokes(N-S) equations coupled with structural motion equations, an aeroelastic analysis of a 70° cropped delta wing before and after vortex breakdown in the time-domain is performed in a state-space. It is shown that the unsteady fluctuation characteristics of the flow become highly obvious after the vortex breakdown,which exert a significant impact on the aeroelastic characteristics of the wing. Before the vortex breakdown, the aeroelastic instability presents itself as just a simple flutter. However, after the vortex breakdown, the aeroelastic phenomenon may be neither a simple flutter, nor a simple buffet induced by the external excitation loads on the wing, but a complex state including both flutter and buffet. As the angle of attack increases, the vortex breakdown location moves forward, and the external excitation loads due to the vortex breakdown rise. The influence of buffet thus increases, and the aeroelastic characteristics become a more obvious phenomenon involving flutter and buffet. Besides, from the analysis of the power spectra density (PSD), it is also found that the fluctuating loads on the wing rise and the frequency of the peak on the PSD decreases as the angle of attack increases.
QUAN Jingge, YE Zhengyin, ZHANG Weiwei
. Comparative Study on Aeroelastic Characteristics of a Cropped Delta Wing Before and After Vortex Breakdown[J]. ACTA AERONAUTICAET ASTRONAUTICA SINICA, 2011
, 32(3)
: 379
-389
.
DOI: CNKI:11-1929/V.20101229.1627.003
[1] 张伟伟, 叶正寅. 大后掠翼前缘涡对其颤振特性的影响[J]. 航空学报, 2009, 30(12): 2263-2268. Zhang Weiwei, Ye Zhengyin. Effects of leading-edge vortex on flutter characteristics of high sweep angle wing[J]. Acta Aeronautica et Astronautica Sinica, 2009, 30(12): 2263-2268. (in Chinese)
[2] Zhang W W, Ye Z Y, Zhang C A, et al. Analysis of supersonic aeroelastic problem based on local piston-theory method[J]. AIAA Journal, 2009, 47(10): 2321-2328.
[3] 王刚,叶正寅. 运用非定常DES方法数值模拟三角翼大迎角流动[J]. 西北工业大学学报, 2008, 26(4): 413-418. Wang Gang, Ye Zhengyin. Study of the unsteady flow around a delta wing at high incidence using detached eddy simulation[J]. Journal of Northwestern Polytechnical University, 2008, 26(4): 413-418. (in Chinese)
[4] Ye Z Y, Zhao L C. Nonlinear flutter analysis of wings at high angle of attack[J]. Journal of Aircraft, 1994, 31(4): 973-974.
[5] 梁强, 叶正寅, 杨永年. 采用非定常N-S方程的翼型颤振特性分析研究[J]. 西北工业大学学报, 2001, 19(3): 341-344. Liang Qiang, Ye Zhengyin, Yang Yongnian. Analysis of airfoil flutter characteristics[J]. Journal of Northwestern Polytechnical University, 2001, 19(3): 341-344. (in Chinese)
[6] 陆志良, 郭同庆, 管德. 跨音速颤振计算方法研究[J]. 航空学报, 2004, 25(3): 214-217. Lu Zhiliang, Guo Tongqing, Guan De. A study of calculation method for transonic flutter[J]. Acta Aeronautica et Astronautica Sinica, 2004, 25(3): 214-217. (in Chinese)
[7] 杨永年, 叶正寅. 带有结构非线性的跨音速翼型颤振特性研究[J]. 计算物理, 2002, 19(2): 173-176. Yang Yongnian, Ye Zhengyin. An investigation of airfoil flutter characteristics with structure nonlinearity at transonic speed[J]. Chinese Journal of Computational Physics, 2002, 19(2): 173-176. (in Chinese)
[8] Gordnier R E, Visbal M. Computation of the aeroelastic response of a flexible delta wing at high angle of attack. AIAA-2003-1728, 2003.
[9] Attar P J, Gordnier R E, Visbal M R. Numerical simulation of the Buffet of a full span delta wing at high angle of attack. AIAA-2006-2075, 2006.
[10] 李劲杰, 杨青, 杨永年. 边条翼布局双垂尾抖振的数值模拟[J]. 空气动力学学报, 2007, 25(2): 205-210. Li Jinjie, Yang Qing, Yang Yongnian. The numerical investigation of twin-vertical tail buffet of strake-wing configuration[J]. Acta Aerodynamics Sinica, 2007, 25(2): 205-210. (in Chinese)
[11] 张伟伟, 叶正寅. 基于非定常气动力辨识技术的气动弹性数值模拟[J]. 航空学报, 2006, 27(4): 579-583. Zhang Weiwei, Ye Zhengyin. Numerical simulation of aeroelasticity basing on identification technology of unsteady aerodynamic loads[J]. Acta Aeronautica et Astronautica Sinica, 2006, 27(4): 579-583. (in Chinese)
[12] 张伟伟, 叶正寅. 基于气动力降阶模型的跨音速气动弹性稳定性分析[J]. 计算力学学报, 2007, 24(6): 768-772. Zhang Weiwei, Ye Zhengyin. Transonic aeroelastic analysis basing on reduced order aerodynamic models[J]. Chinese Journal of Computational Mechanics, 2007, 24(6): 768-772. (in Chinese)
[13] 张伟伟, 叶正寅. 操纵面对跨声速机翼气动弹性特性的影响[J]. 航空学报, 2007, 28(2): 257-262. Zhang Weiwei, Ye Zhengyin. Effect of control surface on aeroelastic characteristics of transonic airfoil[J]. Acta Aeronautica et Astronautica Sinica, 2007, 28(2): 257-262. (in Chinese)
[14] 阎超, 李亭鹤, 黄贤禄. 三角翼上分离及涡流的数值模拟[J]. 力学进展, 2001, 31(2): 227-244. Yan Chao, Li Tinghe, Huang Xianlu. Numerical simula- tion of separation and Vortical flows on delta wings[J]. Advances in Mechanics, 2001, 31(2): 227-244. (in Chinese)
[15] 李劲杰. 边条翼布局双垂尾抖振实验与数值研究. 西安: 西北工业大学航空学院, 2006. Li Jinjie. Experimental and numerical studies on twin-vertical-tails buffet of strake-wing layout. Xi’an: College of Aeronautics, Northwestern Polytechnical University, 2006. (in Chinese)
[16] 王刚. 复杂流动的网格技术及高效、高精度算法研究. 西安: 西北工业大学, 2005. Wang Gang. New type of grid generation technique together with the high efficiency and high accuracy scheme researches for complex flow simulation. Xi’an: Northwestern Polytechnical University, 2005. (in Chinese)
[17] 蒋跃文, 张伟伟, 叶正寅. 基于CFD技术的流场/结构时域耦合求解方法研究[J]. 振动工程学报, 2007, 20(4): 396-400. Jiang Yuewen, Zhang Weiwei, Ye Zhengyin. Study of time-marching method for fluid/structure coupling solution based on CFD technique[J]. Journal of Vibration Engineering, 2007, 20(4): 396-400. (in Chinese)
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