Acoustic scattering cancellation of irregular objects surrounded by spherical layers in the resonant regime

Abstract

In this work, acoustic scattering cancellation is expanded to cases of acoustic waves interacting with non-spherical elastic objects and collections of closely packed objects. The proposed method for achieving this is by using spherical fluid layers to represent the objects as effective spherical targets, with multiple fluid layers and an elastic core, for which scattering cancellation is used to determine the necessary layer properties. Three representative objects are considered here to illustrate this approach: a sphere with dimples, a sphere with bumps, and a bicone. Theoretical results are presented for each of the non-spherical objects in water, which indicate a reduction of 30–40 dB in scattering strength when coated with a two-layer fluid cancellation shell. This cancellation is achieved for objects in the resonant scattering regime, which is characterized by constructive and destructive interference patterns that arise from higher scattering modes. The analytical results are verified using three-dimensional finite element simulations.

Document Details

Document Type
Pub Defense Publication
Publication Date
Oct 27, 2015
Source ID
10.1063/1.4933188

Entities

People

  • Andrea Alù
  • Ashley J. Hicks
  • Matthew D. Guild
  • Michael R Haberman
  • Preston S Wilson

Organizations

  • National Academy of Sciences
  • Office of Naval Research
  • United States Naval Research Laboratory
  • University of Texas at Austin

Tags

Fields of Study

  • Physics

Readers

  • Electromagnetic Wave Scattering and Antenna Radiation Engineering
  • Fluid Dynamics.