利用流-固交界面上的伪瑞利波幅度进行液位检测的实验测量

基于流-固交界面上的伪瑞利波衰减依赖半空间流体性质这一特点,提出了一种利用伪瑞利波幅度测量液位的声学方法,并设计实验对其可行性进行了探讨。首先简要介绍了该方法的理论基础,回顾了前一篇文章的数值模拟工作所得到的重要结论;而后在水槽内进行实验,使用两个源距固定的横波换能器分别激发和接收铝制柱体表面的伪瑞利波,测量了不同液面高度下的脉冲伪瑞利波幅度及其主频偏移,并与数值模拟结果进行了比较。实验结果表明,测量所得的伪瑞利波幅度变化范围略小于数值模拟所得到的结果,但二者在反映变化规律上具有较好的一致性,即:随着液面高度的升高,脉冲伪瑞利波幅度近似呈指数下降,与此同时主频向低频偏移,偏移量近似呈线性规律增大。本文的研究结果从实验上验证了这一检测方法的可行性和有效性。 

An experimental investigation of the method for liquid level detection using the amplitude of pseudo-Rayleigh waves at the fluid-solid interface

Based on the fact that the attenuation of pseudo-Rayleigh waves at the fluid-solid interface is related to the fluid properties, this paper proposes an acoustic method for liquid level detection using the amplitude of pseudo-Rayleigh waves. We firstly introduce the theoretical basis of this method and review the critical conclusions of the numerical study in our previous paper. Then, an experimental measurement is performed to investigate the correlations between the liquid level and the amplitude/frequency-shift of the impulsive pseudo-Rayleigh waves which propagate along the surface of an aluminum cylinder and are excited and recorded by two shear wave transducers with fixed distance. The experimental result shows that, when the distance between source and receiver is constant, the amplitude of the pseudo-Rayleigh wave declines exponentially with the liquid level increases; its central frequency becomes lower linearly at the same time. Therefore, the feasibility and effectiveness of this method are validated.