The Boundary Element Method to provide a numerical solution for the acoustic backscattering produced by Engraulis anchoíta.

JUAN D. GONZÁLEZ; EDMUNDO LAVIA; RUI MARQUES ROJO; SILVIA BLANC; JUAN D. GONZÁLEZ; EDMUNDO LAVIA; RUI MARQUES ROJO; SILVIA BLANC

Buenos Aires

Congreso; Escuela Giambiagi; 2017

Facultad de Ciencias Exactas y Naturales. Universidad de Buenos Aires

The interaction between harmonic acoustic waves propagating in a homogeneous fluid and an object immersed in that medium is governed by Helmholtz scalar differential equation. A possible approach to solve it consists in using the Boundary Element Method (BEM). This approach is particularly useful for high complex geometries of the scatterer object. Then, the object´s real geometry is approximated by mesh structures. When the insonified object is a swimbladdered fish and the medium is seawater, a reasonable assumption based on experimental evidence is to consider that its swimbladder is responsible of most of the backscattered sound. From the acoustical viewpoint, the swimbladder acts as a non-penetrable scatterer with boundary conditions compatible with the Dirichlet case (soft scatterer) in the object-medium interface. This paper presents the results of a computational implementation of the BEM Method applied to the particular problem of acoustic backscattering produced by the swimbladder of a specimen of the species Engraulis anchoita described through images obtained by computed tomography.