Transmission of ultrasound through a single layer of bubbles |
| |
Authors: | V Leroy A Strybulevych M G Scanlon and J H Page |
| |
Institution: | (1) Department of Physics and Astronomy, University of Manitoba, Winnipeg, Canada;(2) Department of Food Science, University of Manitoba, Winnipeg, Canada;(3) Present address: Laboratoire Matière et Systèmes Complexes, Université Paris Diderot-Paris 7 CNRS (UMR 7057), 10 rue Alice Domon et Léonie Duquet, 75205 Paris, France |
| |
Abstract: | We investigate, both experimentally and theoretically, the effect of coupling between resonant scatterers on the transmission
coefficient of a model system of isotropic scatterers. The model system consists of a monodisperse layer of bubbles, which
exhibit a strong monopole scattering resonance at low ultrasonic frequencies. The layer was a true 2D structure obtained by
injecting very monodisperse bubbles (with radius a ∼ 100 μm) into a yield-stress polymer gel. Even for a layer with a low concentration of bubbles (areal fraction, n
a
2 , of 10-20%, where n is the number of bubbles per unit area), the ultrasonic transmission was found to be significantly reduced by the presence
of bubbles (-20 to -50 dB) and showed a sharp minimum at a particular frequency. Interestingly, this frequency did not correspond
to the resonance frequency of the individual, isolated bubbles, but depended markedly on the concentration. This frequency
shift is an indication of strong coupling between the bubbles. We propose a simple model, based on a self-consistent relation,
which takes into account the coupling between the bubbles and gives good agreement with the measured transmission coefficient. |
| |
Keywords: | PACS" target="_blank">PACS 43 35 +d Ultrasonics quantum acoustics and physical effects of sound 43 20 +g General linear acoustics |
本文献已被 SpringerLink 等数据库收录! |
|