Point vortex model for prediction of sound generated by a wing with flap interacting with a passing vortex.
Point vortex model for prediction of sound generated by a wing with flap interacting with a passing vortex.
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用于预测带有襟翼的机翼与经过的涡流相互作用所产生的声音的点涡流模型。
DOI：
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发表时间：
2013
影响因子：
2.4
通讯作者：
Lixi Huang
中科院分区：
文献类型：
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作者：
A. Manela;Lixi Huang
研究了带可动尾翼的刚性机翼与线涡相互作用下二维低马赫数流动的声学特征。采用扭转弹簧将襟翼固定在翼型上，采用薄翼型方法，应用修正的Brown和Michael方程分析了翼型的流固耦合问题。研究发现，翼型上方的入射涡通道以系统固有频率激发襟翼运动，该频率比强迫涡中包含的所有其他频率都要大。采用Powell-Howe类比分析了远场辐射，得到了系统的一级偶极子型特征。结果表明，直接襟翼运动对总声辐射的影响可以忽略不计。系统的特征声学特征以涡声为主，包括相对较强的翼型前后缘与入射涡的相互作用，以及诱导襟翼运动引起的后期尾迹声。与刚性（无襟翼）结构相比较，发现襟翼可以作为声放大器或吸声器，这取决于襟翼-流体固有频率的值。这项研究补充了现有的分析，研究了静态和分离襟翼配置下的声辐射。
Acoustic signature of a rigid wing, equipped with a movable downstream flap and interacting with a line vortex, is studied in a two-dimensional low-Mach number flow. The flap is attached to the airfoil via a torsion spring, and the coupled fluid-structure interaction problem is analyzed using thin-airfoil methodology and application of the emended Brown and Michael equation. It is found that incident vortex passage above the airfoil excites flap motion at the system natural frequency, amplified above all other frequencies contained in the forcing vortex. Far-field radiation is analyzed using Powell-Howe analogy, yielding the leading order dipole-type signature of the system. It is shown that direct flap motion has a negligible effect on total sound radiation. The characteristic acoustic signature of the system is dominated by vortex sound, consisting of relatively strong leading and trailing edge interactions of the airfoil with the incident vortex, together with late-time wake sound resulting from induced flap motion. In comparison with the counterpart rigid (non-flapped) configuration, it is found that the flap may act as sound amplifier or absorber, depending on the value of flap-fluid natural frequency. The study complements existing analyses examining sound radiation in static- and detached-flap configurations.