Modal Decomposition Analysis of Three-Dimensional Transonic Buffet Phenomenon on a Swept Wing
Modal Decomposition Analysis of Three-Dimensional Transonic Buffet Phenomenon on a Swept Wing
复制标题
后掠翼三维跨音速抖振现象的模态分解分析
作者：
Y. Ohmichi;Takashi Ishida;A. Hashimoto
阐明了后掠翼三维跨音速冲击现象的主导流体结构和非定常特性。本文关注的是一个成熟的自助餐现象，而不是一个早期的冲击自助餐（自助餐开始）。纬向分离涡模拟再现了三维自助餐的特征。采用动态模态分解方法提取三维流体结构的模态。为了将动态模式分解应用于大型流体数据集，采用增量适当正交分解基降维。然后，利用压缩感知方法识别优势模式。结果表明，计算得到的流场主要受两种流体结构的控制。一种是在斯特罗哈尔数St 0.2至0.6处振荡的自助餐细胞结构。自助餐细胞在空间上沿展向呈周期性。它们产生于发生较大流动分离的跨中，并以一定角度向翼尖传播。另一个主要原因是……
The dominant fluid structures and unsteady behavior of the three-dimensional transonic buffet phenomenon on a swept wing are clarified. This paper focuses on a well-established buffet phenomenon rather than an incipient shock buffet (buffet onset). Zonal detached-eddy simulation reproduced the features of three-dimensional buffet. Three-dimensional fluid structures were extracted as modes with dynamic mode decomposition. To apply dynamic mode decomposition to the large fluid dataset, the dimensionality was reduced using incremental proper orthogonal decomposition bases. Then, dominant modes were identified using the compressed sensing approach. The results showed that the computed flowfield is dominated by two fluid structures. One is a buffet cell structure oscillating at Strouhal numbers St 0.2 to 0.6. The buffet cells are spatially periodic in the spanwise direction. They are generated at midspan, where a large flow separation occurs, and they propagate at an angle toward the wing tip. The other main f...