Ultrasonic field computation in the presence of a scatterer of finite dimension

Abstract

A recently developed semi-analytical technique called DPSM (Distributed Point Source Method) is improved and used to model the ultrasonic field in a fluid generated by an ultrasonic transducer and scattered by a solid plate of finite dimension. Earlier works on the ultrasonic field modeling by the DPSM technique have been limited to homogeneous fluids or nonhomogeneous media with infinite interfaces. This is the first attempt to model the complete ultrasonic field consisting of incident, reflected, transmitted and diffracted fields by a finite scatterer of any shape or size. No closed form analytical solution exists for ultrasonic field computation in presence of a scatterer and an ultrasonic transducer, both of which can have finite dimensions and any shape. Finite element solution for wave propagation analysis is very time consuming; hence, the semi analytical technique used here appears to be the method of choice for solving such practical problems. The paper shows how the scattered field varies as the acoustic properties and dimensions of the scatterer change.