Reflection and Transmission of Ultrasound at Partially Reflecting Surfaces

摘要

Kirchoff's diffraction theory is used to derive expressions for the behaviour of ultrasonic waves at partially reflecting boundaries. The theory confirms previously derived expressions for monostatic reflection of plane waves by bodies of arbitrary shape and also enables expressions for the more general bistatic reflection and transmission at a partially reflecting, rough, planar boundary between two media to be formulated. It is concluded that close to the directions of specular reflection and Snell refraction the effect of surface roughness on an otherwise planar boundary is to attenuate both the reflected and transmitted sound fields compared to the values each would have assumed were the surface perfectly smooth. Broadly speaking the attenuation increases with surface roughness but for a given roughness the attenuation introduced is also a function of the angles of sound incidence and reflection or refraction. (Atomindex citation 10:470457)