基于鸮翼的仿生翼型噪声机理研究  

Investigation of Noise Mechanism Based on Owl Wing

作　　者：葛长江[1] 葛美辰 梁平[1] 张志辉[1] 任露泉[1] 

机构地区：[1]吉林大学工程仿生教育部重点实验室,长春130025 [2]吉林大学机械科学与工程学院,长春130025

出　　处：《农业机械学报》2013年第S1期292-296,共5页Transactions of the Chinese Society for Agricultural Machinery

基　　金：国家自然科学基金资助项目(31071298)

摘　　要：以具有静音飞行特点的长耳鸮翅膀为模本,利用均方根值构建仿生翼型,研究了解绕鸮翼的流场结构及相关声源。瞬态流场显示上表面发生前缘分离,并在不稳定性的作用下,形成气泡。而且,有涡结构从气泡中分离出来,漂向下游,之后立即破碎,流动也附着在壁面上,形成湍流边界层。类似的情况也发生在下表面,但涡结构漂向更远的下游。而远场噪声计算表明,仿生翼型具有偶极子声源的方向性,声源强度在后缘处最大,说明散射噪声起主要作用。在频谱中,噪声主要集中在中频段,且呈现出与流场结构相应的音调特性。虽然在1kHz左右仿生翼型的噪声才明显下降,但切合了鸮翼可以降低2kHz以上噪声的趋势。A bionic airfoil based on a silent-fight long-eared owl wing was built by using root mean square.The flow structure around the owl wing and the related source were revealed.The unsteady flow showed that a leading-edge boundary layer was separated,and later a bubble was formed due to instability.Furthermore,a vortex detached from the bubble,drifted downstream,and immediately broke down later.A turbulent boundary layer was reattached on the upper surface.A similar evolution occurred on the lower surface,but the vortex drifted further downstream.The corresponding far-field directivities suggested dipole noise and the maximum intensity was at the trailing edge.It suggested that the scattering noise was dominant.In the spectrum,the noise was mainly concentrated in the mid frequency and the tonal characteristics also agreed with the flow structure.The noise of the bionic airfoil started to drop significantly around 1 kHz,and the similar trend was also gained for the natural owl wing with decrease above 2 kHz.

关 键 词：工程仿生 仿生翼型 非稳态流场 噪声机理 散射 

分 类 号：TB533.1[理学—物理]