摘要
研究表明脉动压力是引起气动噪声的主要根源,因此动车组减振降噪要先探究其表面脉动压力。针对微压阻式压力传感器特性及动车组模型试验环境建立了传感器输出模型;利用小波阈值方法进行降噪,通过尺度系数与原始信号的相关性来确定分解层数,根据3σ准则进行小波分解的阈值选取;根据相关系数分离出振动压力和风机噪声压力,最终提取出脉动压力,并利用脉动压力对测点处气动噪声进行预测。研究表明:提取出的脉动压力所预测的气动噪声和传声器所测的噪声变化趋势基本一致,转折频率都为120 Hz,验证了该脉动压力提取方法的正确性,为后续高速动车组压力测量以及减振降噪的研究提供了参考。
The study shows that the pulsating pressure is the main cause of the aerodynamic noise.Therefore,the surface pulsation pressure of the EMU must first be explored.Based on the characteristics of micro piezoresistive pressure sensor and the model test environment of EMU model,the sensor output model was established.The wavelet threshold method was used to reduce the noise.The decomposition level was determined by the correlation between the scale coefficient and the original signal,and the threshold of wavelet decomposition was selected according to the criterion.According to the correlation coefficient,the vibration pressure and the noise pressure of the fan were separated.Finally,the pulsating pressure was extracted,and the fluctuating pressure was used to predict the aerodynamic noise at the measuring point.The results show that the variation trend of aerodynamic noise predicted by pulsating pressure and the noise measured by the microphone is basically the same.The turning frequency is 120 Hz,which validates the correctness of the pulsating pressure extraction method.It provides reference for the study of the pressure measurement and the study of vibration and noise reduction in the following high speed EMU.
作者
同晓雅
陈春俊
杨劼立
张振
TONG Xiao-ya;CHEN Chun-jun;YANG Jie-li;ZHANG Zhen(College of Mechanical Engineering,Southwest Jiaotong University,Chengdu 610031,China)
出处
《仪表技术与传感器》
CSCD
北大核心
2019年第2期86-89,93,共5页
Instrument Technique and Sensor
基金
国家自然科学基金项目(51475387)
关键词
动车组模型
表面脉动压力
小波阈值
EMD
相关系数
EMU model
surface pulsating pressure
wavelet threshold
EMD
correlation coefficient
