摘要
用光学法和发射 接收法研究了水与流体饱和孔隙介质界面上声波的非镜面反射声场 .测量了入射角θi 为 1 6°— 80°范围内的反射系数R ,记录了θi 在Rayleigh波临界角θc附近± 4°范围内两束反射波的反射角、波束位移Δ、波形和频谱 .实验发现 :(1 )在θc 附近±4°范围内 ,观察到θi两束反射波A和B ,其中波束B沿界面有波束位移Δ ,实验测出Δ随θi增大而减小 ,并非在θi=θc 时最大 .(2 )反射角等于θi 的波束的频谱很接近于入射波的频谱 ,反射角等于θc 的波束的频谱相对于入射波有频谱的负偏移 .(3)波束A的相位与发射换能器直达波的相位一致 。
In this paper,the non specular acoustic reflected field on a Water FSPM (fluid saturated porous media interface by the optical method and the transmitter receiver method. The reflection coefficient R was measured for incident angle of 16°～80°. The reflection angles of two beams, their beam displacements, wave forms and spectra were recorded in the range of the incident angle ±4° near the Rayleigh critical angle θ c. The experiment was found (1) that for the range θ i of ±4° near θ i two reflected beams A and B were observed. The measured displacement Δ of the beam B decreases as the incident angle θ i increases and is not a maximum at θ c= θ i, (2) that spectrum of the beam with the reflection angle equal to θ i is much closed to that of the incident beam, and the spectrum of the other beam with the reflected angle equal to θ c has a negative shift to that of the incident beam, (3) that the phase of beam A is the same as that of directly received from transmitter, and the phase of the beam B is inverse to that of beam A . [
出处
《地球物理学报》
SCIE
EI
CAS
CSCD
北大核心
2001年第1期83-92,共10页
Chinese Journal of Geophysics
基金
国家自然科学基金项目!(49674 2 3 7) .
