Acoustic method for obtaining the pressure reflection coefficient using a half-wave layer.
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.
Institute of Electrostatics and Special Power, Dalian University of Technology, Dalian 116024, China. jiaxinliu@mail.dlut.edu.cn
Jia-xin
JX
Liu
Zhi-qiang
ZQ
Wang
Guo-feng
GF
Li
Ning-hui
NH
Wang