摘要
为了更好地体现后视镜的造型风格,某自主品牌在新车开发过程中,采用非常规的镂空镜柄设计.旨在通过仿真和风洞试验相结合的方法,对该后视镜镜柄的气动特性进行研究并优化,以降低车内驾驶员处的声学响应.经过仿真发现,原始镜柄造型存在严重的气流分离,并伴随严重的回旋涡流,对风噪非常不利,基于此提出2种优化方案,有效改善了镜柄处速度分布梯度和气流分离.试验结果表明:2种优化方案对声压级和语音清晰度有很好的改善效果,车内声压级分别降低0.21 dBA和0.18 dBA,语音清晰度均提高1.5％;与此同时,采用声学麦克风阵列成像准确定位到了啸叫所在部件和对应频段,通过改变表面粗糙度的方案,使优化方案二的贡献量进一步提升0.02 dBA和0.6％.研究结果不仅验证了该仿真方法在项目开发过程中的可信度,而且可为后视镜镂空镜柄的设计和优化提供参考依据.
Abstract
To better reflect the styling of the rearview mirrors,a domestic brand adopts an unconventional hollow mirror handle design in its new vehicle development.This paper studies and optimizes the aerodynamic characteristics of the rearview mirror handle by simulation and wind tunnel test to reduce the acoustic response in the vehicle's driver's cockpit.Our simulation reveals a serious airflow separation in the original mirror handle molding,accompanied by serious swirling vortex,which create unfavorable wind noises.To address the problem,this paper proposes two optimized schemes which effectively improve the velocity distribution gradient and airflow separation at the mirror handle.Our experimental results show the two optimized schemes substantially enhance the sound pressure level and speech clarity.The interior sound pressure level is reduced by 0.18 dBA and 0.21 dBA respectively,and both articulation indexes are improved by 1.5％.Meanwhile,the acoustic microphone array imaging is employed to accurately locate the component in which the roar occurs and the corresponding frequency band.By optimizing the surface roughness scheme,the contribution of the second optimized scheme is further increased by 0.02 dBA and 0.6％.Our research results validate the credibility of the simulation method in the project development process and provide some references for the design and optimization of the hollow mirror handles of rearview mirrors.
基金项目
国家重点研发计划项目(2022YFE0208000)
国家科技期刊平台
NSTL
万方数据