为了明确车用爪极发电机在高转速下不同部件对气动噪声的影响,对车用爪极发电机的气动噪声进行了数值模拟研究,并进行了车用爪极发电机的空载声功率实验,验证了数值模拟的准确性；采用有无前、后风扇、爪极及采用圆柱包络体代替爪极方案确定各阶次噪声的来源,明确了前后风扇、爪极对不同阶次噪声的贡献水平。结果表明：在高转速下偶极子是主要噪声源类型；前风扇主要影响8、10、12、16阶次气动噪声,去除前风扇时12、16阶次分别降低了6.54dBA和9.04dBA；后风扇主要影响6、8、10阶次噪声,去除后风扇分别下降了11.75dBA、2.42dBA、7.38dBA；有无爪极时对气动噪声影响较小,但采用圆柱包络体代替爪极时对气流流动产生影响,使得8阶次噪声有一定变化；这也表明前后风扇是气动噪声产生的重要源头。

In order to understand the influence of different parts on the aerodynamic noise of the claw alternator for vehicle at high speeds, this research studies the aerodynamic noise characteristics of the claw alternator. The no-load acoustic power level experiment of the claw alternator for vehicle is carried out to verify the accuracy of the numerical simulation. The noise sources of each order are determined by using with or without front and rear fan blades, claw and cylinder envelope instead of claw pole. The contribution of front and rear fan blades and claw to different orders of noise are Clarified. The results show that dipole is the main noise source at high speed. The front blade mainly affects the aerodynamic noise in 8th, 10th, 12th and 16th order. When the front fan is removed, the aerodynamic noise in 12th and 16th order is reduced by 6.54dBA and 9.04dBA, respectively. The rear fan mainly affects the aerodynamic noise in 6th, 8th and 10th order. When the rear fan is removed, the aerodynamic noise in 6th, 8th and 10th order is reduced by 11.75dBA, 2.42dBA and 7.38dBA, respectively. The influence on the aerodynamic noise is small with or without claw, but the flow field is affected when the cylinder envelope is used to replace the claw pole, and the 8th order noise has a certain change. It also shows that the front and rear fans are main sources of the aerodynamic noise.

U46

国家自然科学基金资助项目(51976055)；湖南省自然科学基金面上项目(2019JJ40103)；湖南省教育厅青年项目(18B359).