障碍物对液体表面波检测的影响研究  

Study on the Influence of Obstacles on Liquid Surface Acoustic Wave Detection

作　　者：李能能[1] 

机构地区：[1]西安航空学院电子工程学院,陕西西安710077

出　　处：《西安航空学院学报》2016年第5期82-86,共5页Journal of Xi’an Aeronautical Institute

摘　　要：为了研究障碍物对液体表面波检测的影响,本实验将一矩形障碍物放置在表面波的传播方向上,激光斜入射到表面波激发器与障碍物之间的区域,观察到衍射图样。当表面波传播到障碍物时发生反射,根据波的叠加原理,障碍物与激发器的距离不同,叠加后的表面波振幅也不同。通过改变障碍物与激发器之间的距离,观察屏上得到不同的衍射图样。利用计算机软件Matlab对不同的衍射图样扫描,得到不同的光强分布。根据光强分布及贝塞尔函数规律,得出不同距离处同一入射点的液体表面波振幅。实验结果表明:液体表面波振幅随着障碍物与激发器之间的距离增大以指数规律减小。In order to study the influence of obstacles on the liquid surface acoustic wave detection, a rectan- gular obstacle is placed in the direction of propagation of the liquid surface acoustic wave （SAW）. Diffraction patterns from SAW are observed when the laser beam shines in the area between the wave excitation and the rectangular obstacle. The reflection occurs when the surface wave propagates to the obstacle. According to the superposition principle of the wave, the amplitude of the surface wave varies with the change of the distance between the obstacle and the exciter. Different diffraction patterns are obtained on the observation screen through changing the distance between the obstacle and the exciter. Different light intensity distributions are obtained through scanning different diffraction patterns via computer software. Accord- ing to the light intensity distribution and Bessel＇s function, the liquid surface wave amplitude of the same incident point at different distances is obtained. Experiment results show that the surface acoustic wave amplitude decreases exponentially as the distance between the exciter and the obstacle increases.

关 键 词：障碍物 液体表面声波 振幅 衍射 衰减 

分 类 号：O436[机械工程—光学工程] O357.43[理学—光学]