孙贵洋 陈二云 杨爱玲

摘要：针对锯齿前缘结构调控叶片近壁面流场特性，以 NACA0018叶片为对象，采用大涡模拟方法研究不同锯齿前缘结构对叶片近壁面流场的影响机制。获得了来流速度为30 m· s?1、雷诺数为513440、0°攻角下叶片近壁面流场分布特性。分析了锯齿前缘和叶片前缘和尾缘处压力脉动及分离涡的影响。数值结果表明：对正弦波齿而言，随着振幅的增大，在波谷处的小涡开始向前缘移动，整体上小尺度涡增多，前缘近壁面压力脉动增大，尾缘近壁面压力脉动减小;对叠加波形齿而言，尾迹涡进一步破碎，厚度变薄，叶片表面出现破碎的小尺度涡，在尾缘处叶片压力脉动幅值下降最为明显，且未出现明显的窄带尖峰。

关键词：尾迹涡;压力脉动;锯齿前缘;叠加波形

中图分类号： TB17    文献标志码： A

Numerical study on the flow separation controlling by sawtooth leading edge of the blade

SUN Guiyang ，CHEN Eryun，YANG Ailing

（School of Energy and Power Engineering/Shanghai Key Laboratory of Multiphase Flow and Heat Transfer inPower Engineering， University of Shanghai for Science and Technology， Shanghai 200093， China）

Abstract：Aiming at the flow field characteristics of the near-wall blade surface controlled by sawtooth leading edge， taking the NACA0018 blade as the object， the influence of sawtooth leadingedge on the near-wall flow field of the blade was studied by large eddy simulation method. Thedistribution characteristics of flow field near the blade wall at a flow velocity of 30 m · s  ，  a Reynolds number of 513440， and an angle of attack of 0° were obtained. The influence of the sawtooth leading edge on the pressure fluctuation and the separation vortex at the leading and trailing edges of the blade was analyzed. The numerical results show that for the sine-shaped sawtooth， as the amplitude increases， the small-scale vortex at the wave trough moves to the frontedge， which increases generally. The pressure fluctuation near the front wall increases while thepressure fluctuation near the wall of the trailing edge decreases. For the superimposed sawtooth， the wake vortex is further broken， whose thickness decreases. And the small-scale broken vortices appear on the blade surface. The pressure fluctuation amplitude at the blade trailing edge decreases obviously， and there is no obvious narrow-band spike.

Keywords：wake vortex; pressure fluctuation; sawtooth leading edge; superimposed wave

随着人民生活的日益提高，噪声问题慢慢进入人们的视野，风机、飞机、风力机及空调压缩机的噪声给人们的日常生活带来了诸多不便。叶片气动噪声是这类机械最主要的噪声源。国内外学者在研究叶片自噪声时，对叶片尾缘自噪声关注度颇高，也采取了许多降噪措施，例如：尾缘锯齿、多孔介质和刷式尾缘等，并取得了显著成果[1]。Moreau 等[2]以平板为对象，研究雷诺数在1.6×105～4.2×105范围内锯齿对平板噪声的影响，发现尾缘锯齿可以削弱低频范围内的宽频噪声约3 dB，同时削弱尾涡脱落噪声约13 dB。 Chong 等[3]探究了层流叶片窄带单峰噪声产生机理与尾缘锯齿对叶片窄带单峰噪声的影响，并指出原始叶片的声学反馈回路，在尾缘处发生了衍射，出现了 T?S 波，从而解释了寬带噪声中“驼峰”形成的原因。……