Three-Dimensional Global Stability Analysis and Bio-Mimetic Control of Buffet Phenomena via Wings with Wavy Leading and Trailing Edges

跨音速冲击是一种不稳定性，其特征是飞机机翼在跨音速条件下随着迎角的增加而发生周期性的自持续冲击振荡。控制和抑制颤振对提高飞机的整体性能和安全性具有重要影响。为了控制冲击，我们在这里提出了波浪状的前缘和后缘翅膀，试图模仿座头鲸胸鳍的性能增强能力。本文首先对周期（无限宽）机翼在受振条件下进行了波浪形前缘和后缘的影响试验，结果表明，波浪形前缘对机翼的不稳定性有较好的抑制作用，而后缘对机翼的不稳定性影响较小。因此，波浪前缘被应用于有限翼在受振条件下，并研究了不同特征参数（即波浪振幅和波长，波浪向展向起始位置）的影响。有限机翼上的波浪前缘似乎在抑制冲击方面效果较差，但无论如何都减少了冲击振荡的幅度。

Transonic buffet is an instability characterized by periodic self-sustained shock-oscillations that occur on aircraft wings at transonic conditions for increasing angles of attack. Controlling and suppressing buffet can have a significant impact in improving the aircraft overall performance and safety. To control buffet, we here proposed wings with wavy leading- and trailing edges, in the attempt to mimic the performance enhancement capabilities of the humpback whale pectoral fins. The effects of wavy leading- and trailing-edges was first tested on periodic (infinitely wide) wings at buffet conditions and it was found that wavy leading-edges are successful in suppressing the instability, while wavy trailing-edges have little or not effect. Wavy leading-edges have therefore been applied to finite wings at buffet conditions and the effect of different characteristic parameters (i.e. waviness amplitude and wavelength, waviness spanwise starting location) has been investigated. Wavy leading-edges on finite wings seem to be less effective in suppressing buffet, but the amplitude of the shock-oscillations is anyway reduced.