Tejedor Sastre María Teresa, Vanhille Christian
Universidad Rey Juan Carlos, Tulipán, s/n. 28933 Móstoles, Madrid, Spain.
Universidad Rey Juan Carlos, Tulipán, s/n. 28933 Móstoles, Madrid, Spain.
Ultrason Sonochem. 2017 Nov;39:597-610. doi: 10.1016/j.ultsonch.2017.05.009. Epub 2017 May 13.
The objective of this work is to develop versatile numerical models to study the nonlinear distortion of ultrasounds and the generation of low-ultrasonic frequency signals by nonlinear frequency mixing in two and three-dimensional resonators filled with bubbly liquids. The interaction of the acoustic field and the bubble vibrations is modeled through a coupled differential system formed by the multi-dimensional wave equation and a Rayleigh-Plesset equation. The numerical models we develop are based on multi-dimensional finite-volume techniques and a time discretization carried out by finite differences. Numerical experiments are performed for complex modes in many different cavities considering different kinds of boundary conditions and taking advantage of the dispersive character of the bubbly fluid to match specific resonances of the cavities. Results show the distribution of fundamental and harmonics for single frequency excitation and difference-frequency component for two-frequency excitation that are promoted by the strong nonlinearity of the bubbly medium. The numerous simulations analyzed suggest that the new numerical models developed and proposed in this paper are useful to understand the behavior of ultrasounds in bubbly liquids for sonochemical processes and applications of nonlinear frequency mixing.
这项工作的目标是开发通用的数值模型，以研究超声波的非线性失真，以及在充满气泡液体的二维和三维谐振器中通过非线性频率混合产生低频超声信号。通过由多维波动方程和瑞利 - 普莱斯方程形成的耦合微分系统对声场与气泡振动的相互作用进行建模。我们开发的数值模型基于多维有限体积技术和通过有限差分进行的时间离散化。考虑到不同类型的边界条件，并利用气泡流体的色散特性来匹配腔体的特定共振，针对许多不同腔体中的复杂模式进行了数值实验。结果显示了单频激励下基波和谐波的分布，以及双频激励下由气泡介质的强非线性促进产生的差频分量。所分析的大量模拟表明，本文开发并提出的新数值模型有助于理解超声在气泡液体中的行为，用于声化学过程和非线性频率混合应用。
