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Published on: December 3, 2016
Acoustic method for obtaining the pressure reflection coefficient using a half-wave layer
Jia-xin Liu1, Zhi-qiang Wang, Guo-feng Li
1Institute of Electrostatics and Special Power, Dalian University of Technology, Dalian 116024, China. jiaxinliu@mail.dlut.edu.cn
Abstract:
This paper describes a method for obtaining the pressure reflection coefficient by using a half-wave layer. Two transducers were placed in reference liquid and test liquid respectively. The reference and test liquid were separated by the thin half-wave layer. Both transducers could operate in two modes. One acted as a transmitter and worked in pulse-echo mode, and the other operated in receiver mode. By adjusting the frequency of drive signal according to the thickness and material property of the half-wave layer, it was possible to generate the maximum interference signal of multiple waves reflected at the two interfaces of the layer. Therefore, the amplitude of reflection wave in steady-state depended only on the reflection coefficient at the interface between the half-wave layer and the test liquid. The effects of the signal-to-noise-ratio and the half-wave layer attenuation on the uncertainty characteristics of the pressure reflection coefficient were discussed. The experimental results showed high accuracy for measurement of reflection coefficient.
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