Numerical study of acoustically driven bubble cloud dynamics near a rigid wall
| Autor: | Chao-Tsung Hsiao, Georges L. Chahine, Jingsen Ma |
|---|---|
| Rok vydání: | 2018 |
| Předmět: |
Physics
Collective behavior Acoustics and Ultrasonics Bubble Organic Chemistry Natural frequency 02 engineering and technology Mechanics 021001 nanoscience & nanotechnology 01 natural sciences 010305 fluids & plasmas Physics::Fluid Dynamics Inorganic Chemistry Classical mechanics Amplitude Excited state Cavitation 0103 physical sciences Chemical Engineering (miscellaneous) Environmental Chemistry Radiology Nuclear Medicine and imaging 0210 nano-technology Excitation Ambient pressure |
| Zdroj: | Ultrasonics Sonochemistry. 40:944-954 |
| ISSN: | 1350-4177 |
| DOI: | 10.1016/j.ultsonch.2017.08.033 |
| Popis: | The dynamics of a bubble cloud excited by a sinusoidal pressure field near a rigid wall is studied using a novel Eulerian/Lagrangian two-phase flow model. The effects of key parameters such as the amplitude and frequency of the excitation pressure, the cloud and bubble sizes, the void fraction, and the initial standoff distance on the bubbles’ collective behavior and the resulting pressure loads on the nearby wall are investigated. The study shows that nonlinear bubble cloud dynamics becomes more pronounced and results in higher pressure loading at the wall as the excitation pressure amplitude increases. The strongest collective bubble behavior occurs at a preferred resonance frequency. At this resonance frequency, pressure peaks orders of magnitudes higher than the excitation pressure result from the bubble interaction when the amplitude of the pressure excitation is high. The numerically obtained resonance frequency is significantly different from the reported natural frequency of a spherical cloud derived from linear theory, which assumes small amplitude oscillations in an unbounded medium. At high amplitudes of the excitation, the resonance frequency decreases almost linearly with the ratio of excitation pressure amplitude to ambient pressure until the ratio is larger than one. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|
Full Text from ScienceDirect