title: Experiment and modeling of translational dynamics of an oscillating bubble cluster in a stationary sound field.
abstract: Translational motion of an oscillating bubble cluster under sound irradiation is studied experimentally and is modeled in the framework of the classical approach of Bjerknes. An experimental technique is proposed to observe bubble cluster formation and its translational dynamics interacting with wall boundaries due to the secondary Bjerknes force. The translational motion observed in the experiment is modeled by extending the classical theory of Bjerknes on a single bubble; a bubble cluster is treated as a single bubble. The extended Bjerknes theory is shown to allow us to predict the overall trajectory of the cluster translating toward a wall of finite acoustic impedance by tuning acoustic energy loss at the wall. The drag force turns out to be unimportant for the translation of a millimeter-sized cluster that we observed.
authors.affiliation: Department of Mechanical Engineering, Keio University, Yokohama 2238522, Japan. Electronic address: sugita@keio.jp.
authors.forename: Naohiro
authors.initials: N
authors.lastname: Sugita
authors.affiliation: Department of Mechanical Engineering, Keio University, Yokohama 2238522, Japan.
authors.forename: Keita
authors.initials: K
authors.lastname: Ando
authors.affiliation: Department of Mechanical Engineering, Keio University, Yokohama 2238522, Japan.
authors.forename: Toshihiko
authors.initials: T
authors.lastname: Sugiura
keywords: Bubble cluster dynamics; High-speed imaging; Secondary Bjerknes force; Sonication