旋转叶片高频涡脱落噪声源的双阵列声成像试验研究

旋转叶片的涡脱落噪声是一类典型的指向性声源,但由于叶片的旋转尚无法准确测量旋转叶片涡流噪声的指向性。利用两个平面阵列在叶片旋转面的平行和垂直两个方向对声源进行了声成像试验研究。试验中选择不同的叶片旋转方位角位置对涡脱落气动噪声进行波束形成声成像,通过比较声源在叶片不同方位角以及不同阵列方向的声成像结果验证了旋转叶片涡脱落噪声的指向性,并且分析了不同的叶片旋转方位角对涡脱落噪声的影响。试验结果验证了双阵列声成像测量方案的可行性和有效性,成像结果的对比表明使用的NACA0012桨叶在2.5 kHz下的旋转气动噪声源为指向性声源。

Dual-array acoustic imaging tests of high frequency vortex shedding noise source for rotating blades

The vortex shedding noise of rotating blade is a kind of typical directional sound source.However,the directivity of vortex shedding noise can’t be measured accurately due to blade rotating.Here,two planar arrays were used to study the acoustic imaging of sound source in two directions of parallel and vertical to the rotating surface of blade.In tests,different blade rotation azimuth positions were selected to perform beamforming acoustic imaging of vortex shedding aerodynamic noise.The directivity of vortex shedding noise was verified by comparing acoustic imaging results under different blade azimuth angles and array directions,and effects of different blade rotation azimuth angles on vortex shedding noise were analyzed.The test results verified the feasibility and effectiveness of the dual-array acoustic imaging measurement scheme.The comparison of imaging results showed that the rotating aerodynamic noise source of NACA0012 blade at 2.5 kHz is directional.