中低频噪声信号的传播衰减分析  

Studying on Propagation Attenuation of Medium and Low Frequency Noise Signal

作　　者：陈娟娟[1] 欧阳玉花[1] 张孝强[1] 王涛[1] 廖涛[1] 

机构地区：[1]兰州交通大学数理学院,甘肃兰州730070

出　　处：《兰州交通大学学报》2016年第4期122-126,142,共6页Journal of Lanzhou Jiaotong University

基　　金：国家自然科学基金(61561043);甘肃省自然科学基金(1508RJZA079)

摘　　要：声音在大气中传播的过程中,因介质吸收而衰减.不同的大气环境,介质吸收会有很大差别.在大气中传播较长距离的可听频段声波,大气吸收的影响不容忽视.基于分子动力学、振动弛豫过程、Navier-Stokes方程、Laplace方程以及声传播理论,计算了复杂大气环境下的吸声系数,分析了吸声系数随环境参数的变化规律.最后实测了两种不同频率的汽车喇叭声信号传播不同距离的声强,并计算出相应的吸声系数,所得结果与理论值吻合.In the process of sound propagation in the atmosphere, it is necessary to consider absorption and attenuation. In different atmospheric environments, sound absorption is different. The impact of atmospheric absorption cannot be ignored for audible frequency sound waves propagating long way in the atmosphere. The absorption coefficients in air are calculated and their variations with environmental factors are analyzed based on molecular kinetics, vibrational relaxation processes,Navier-Stokes equations,Laplacian and the propagation theory of acoustic waves. The environmental factors mainly include air pressure,temperature and humidity. A detailed analysis of the environmental effect of air pressure on the absorption of sound is presented. The figures make it possible to estimate accurately the absorption at any values of atmospheric pressure in the range 60 kPa to the pressure of standard atmosphere （p0）. Moreover,the sound intensity of car honking signal is also measured. The measure locations are selected in accordance with different propagation distances. The car honking signal is respectively generated by two cars＂ horns, and its frequency is different. And then the corresponding absorption coefficient is calculated. The results obtained are in good agreement with the theoretical value.

关 键 词：吸声系数 温度 湿度 压强 汽车喇叭声 

分 类 号：O42[理学—声学]