浓悬浮体中多次散射对声波能量传输的影响

本文应用类似于光学中的传输问题建立起声波传输方程,用以解决声波在浓悬浮体中传播时考虑了微粒间的多次散射后声波能量的透射和反射问题。该方法较目前声学中采用的处理方法简捷,所依据的物理图像清晰,适用于粒子线度与波长的比为任意值的情况。本文还以刚性球形悬浮粒子为例,计算了声波的透射和反射与程长的关系,得出在浓度不太大时(散射系数×程长<0.256),当ka<1时不考虑多次散射不会产生很大误差,ka=3时,由于多次散射影响,散射系数减小5％,ka=5时散射系数减小14％。浓度增大时散射系数逐渐减小。此外还讨论了微粒线度分布、声接收器后部悬浮体的散射等对声能传递的影响。     

THE EFFECT OF MULTIPLE SCATTERING ON ACOUSTIC ENERGY TRANSFER IN HIGHLY CONCENTRATED AQUEOUS SUSPENSIONS

An acoustic energy transfer equation has been set up to solve the multiple scattering problem inacoustic wave transfer in highly concentrated aqueous suspensions.This method is easier to handle than theusual one,and can be used for any values of the ratio of particle size to wave length.It has been found thatwhen the multiple scattering is considered the scattering coefficient is decreased by 5% to 14% in the case ofka=3 to 5 and the product of the coefficient and the path length less than 0.256.As the concentrationincreases the scattering coefficient becomes even less.The influence of the particle size distribution,absorption and inhomogeneity in suspensions on the scattering coefficient is discussed.