Effect of a fluid wedge on the wave propagation along a fluid-solid interface: A modeling approach

Interaction between a bounded ultrasonic beam and a liquid wedge over a solid half-space is studied. A semi-analytical technique called Distributed Point Source Method (DPSM) is adopted for modeling the ultrasonic field in a wedge shaped fluid structure on a solid half space. This study is important for analyzing the ultrasonic waves used for the nondestructive inspections of partially immersed structures and for studying the effect of underwater ultrasonic or acoustic wave experiments on marine lives near the shore. The problem geometry considers a bounded acoustic beam striking a fluid-solid interface between a fluid wedge and a solid half-space. Solution of this problem is beyond the scope of the currently available analytical methods when the beam is bounded. However, it is important to model the bounded beams because in all underwater communications and inspections bounded beams are used. Currently only numerical method [Boundary Element Method (BEM) or Finite Element Method (FEM)] based packages (e.g. PZFlex) are in principle capable of modeling ultrasonic fields in such structures. However, these packages are not very accurate and are very CPU intensive for high frequency ultrasonic problems. At high frequencies FEM and BEM based packages require huge amount of computation memory and time for their executions that DPSM technique can avoid. Effect of the angle variation between the fluid-solid interface and the fluid wedge on the wave propagation characteristics is studied.