摘要
为了提高汽车风洞外场声源识别精度,对因实际流场与空风洞之间区别产生的偏差进行分析.关注汽车绕流场与射流剪切层的速度分布,分别对车辆所在自由空间、空风洞与带实际车辆的风洞3种流场进行数值仿真及试验验证.通过无限薄剪切层及实际流场分层声传播模型,预测有无车辆两种风洞状态下的声漂移量,并与实际整车声学风洞声传播试验结果进行比较.结果表明,放入车辆后,风洞势流核心区因受汽车阻塞而流场速度分布不均匀,进而剪切层区域流场受到汽车绕流场干扰而外扩.进行实际流场分层修正后,车表后方声源漂移结果精度大幅提高,能有效提高实际风洞外场声源识别精度.
In order to improve the accuracy of outfield sound source identification in automobile wind tunnel,the deviation caused by the difference between actual flow field and empty wind tunnel is analyzed.Focusing on the velocity distribution of flow around vehicle and jet shear layer,numerical simulation and experimental verification were carried out on 3 kinds of flow fields,including free space where vehicle is located,empty wind tunnel and wind tunnel with actual vehicle.The amounts of sound drift in wind tunnel with or without vehicles were predicted by using infinite thin shear layer model and layered flow field sound propagation model.The predicted sound drift quantities were compared with actual full-scale acoustic wind tunnel sound propagation test results.The results show that,after vehicle was placed in the wind tunnel,the flow field velocity distribution in core area of potential flow was uneven due to obstruction of the vehicle,and then the flow field in shear layer was disturbed by flow field around vehicle.After stratified correction of the actual flow field,the accuracy of sound drift quantity at rear sound source of vehicle body is greatly improved,which can effectively improve the identification accuracy of the actual wind tunnel.
作者
沈哲
余昊晟
王勇
彭里奇
杨志刚
SHEN Zhe;YU Haosheng;WANG Yong;PENG Liqi;YANG Zhigang(State Key Laboratory of Vehicle NVH and Safety Technology,Chongqing401122,China;Postdoctoral Station of Mechanical Engineering,Tongji University,Shanghai201804,China;Shanghai Automotive Wind Tunnel Center,Tongji University,Shanghai201804,China)
出处
《湖南大学学报(自然科学版)》
EI
CAS
CSCD
北大核心
2021年第12期29-35,共7页
Journal of Hunan University:Natural Sciences
基金
汽车噪声振动和安全技术国家重点实验室开放基金项目(NVHSKL-202003)
上海市重点实验室项目(18DZ2273300),。
关键词
车辆噪声测量
风洞
阻塞效应
声源漂移
vehicle noise measurement
wind tunnels
blockage effect
sound source drift