Propagation of acoustic wave in viscoelastic medium permeated with air bubbles

• 来源期刊: 中国物理（英文版）
• 关键词: acoustic wave viscoelastic medium bubble nonlinearity
• 年，卷（期）: 2006,（2）
• 页码范围: 412-421
• 页数: 10页
• 语种: 英文

摘要

Based on the modification of the radial pulsation equation of an individual bubble, an effective medium method (EMM) is presented for studying propagation of linear and nonlinear longitudinal acoustic waves in viscoelastic medium permeated with air bubbles. A classical theory developed previously by Gaunaurd (Gaunaurd GC and (U)berall H, J. Acoust. Soc. Am., 1978; 63: 1699-1711) is employed to verify the EMM under linear approximation by comparing the dynamic (i.e. frequency-dependent) effective parameters, and an excellent agreement is obtained. The propagation of longitudinal waves is hereby studied in detail. The results illustrate that the nonlinear pulsation of bubbles serves as the source of second harmonic wave and the sound energy has the tendency to be transferred to second harmonic wave. Therefore the sound attenuation and acoustic nonlinearity of the viscoelastic matrix are remarkably enhanced due to the system's resonance induced by the existence of bubbles.