Effects of Interaction between Two Bubble Scatterers

Abstract

The backscattering of sound from two regularly arranged bubbles is studied theoretically and experimentally. In wall-controlled laboratory experiments a bistatic acoustic system is used to interrogate the scatterers, which are placed on a very fine thread at the same distance d from the combined beam axis of the set of transmitting and receiving transducers. The radius of each bubble is 585 micrometers. The frequency range is 80-140 kHz, and d is varied so that the variable kd spans the range 0.2-21, where k is the acoustic wave number. Scattering calculations are carried out using an exact, closed-form solution derived from the multiple scattering series. Several experiments are performed, and the results are in close agreement with the calculations. It is verified that multiple scattering induces an oscillatory behavior about the exact coherent scattering level, with decreasing amplitude for increasing kd. For interbubble distance 2d = lambda/2 the backscattered radiation is maximized, while for 2d < lambda/2 the radiation is reduced considerably. These and other effects are discussed.

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Document Details

Document Type
Technical Report
Publication Date
Mar 03, 2000
Accession Number
ADA375668

Entities

People

  • George Kapodistrias
  • Peter Hans Dahl

Organizations

  • University of Washington

Tags

Communities of Interest

  • Advanced Electronics
  • Air Platforms

DTIC Thesaurus Topics

  • Acoustic Fields
  • Acoustic Waves
  • Agreements
  • Amplitude
  • Backscattering
  • Coherent Scattering
  • Experimental Data
  • Far Field
  • Frequency
  • Frequency Response
  • Intensity
  • Measurement
  • Physics Laboratories
  • Radiation
  • Resonant Frequency
  • Scattering
  • Transducers

Fields of Study

  • Physics

Readers

  • Acoustical Oceanography.
  • Fluid Dynamics.
  • Underwater engineering and Marine Technology.