双泡耦合声空化动力学过程模拟

Simulation of dynamic process of double bubble coupled acoustic cavitation

为了对双泡耦合的声空化过程进行模拟,本文从流体动力学控制方程和流体体积分数模型出发,在Fluent软件中构建双泡耦合超声空化三维有限元仿真模型,对超声波驱动下流体中双泡耦合声空化动力学过程进行数值模拟,并通过对空化气泡周围声场的变化进行分析研究双泡耦合声空化的非线性动力学特性.结果显示:在超声波驱动下,球形气泡先缓慢扩张,扩张到最大半径后迅速收缩直至溃灭;耦合双气泡间存在相互作用力,使得空化气泡的扩张受到抑制、气泡收缩时间增长;空化气泡在收缩阶段的能量转换能力增强,相比单气泡声空化,耦合双气泡溃灭时气泡内部的压强更大.本文分析结果将为超声空化泡群的动力学过程模拟提供参考.

In order to simulate the acoustic cavitation process of double-bubble coupling,based on the fluid dynamics governing equation and fluid volume fraction model,this paper proposes a three-dimensional finite element simulation model of double-bubble coupled ultrasonic cavitation in Fluent software,and numerically simulates the dynamic process of double-bubble coupled acoustic cavitation in fluid driven by ultrasonic wave.The nonlinear dynamic characteristics of coupled acoustic cavitation with double bubbles are studied by evaluating the variation of the acoustic field around the cavitation bubble.The results indicate that under the ultrasonic drive,the spherical bubbles gradually widen first to the maximal radius,then shrink swiftly,and finally collapse.There is an interaction force between the paired double bubbles,which inhibits the expansion of cavitation bubbles and increases the bubble contraction time.The ability of the cavitation bubble to converse the energy is strengthened in the contraction stage.Compared with the acoustic cavitation of the single bubble,the pressure inside the bubble is expanded when the coupled double bubble collapses.The analysis results in this paper will provide the reference for the dynamic process simulation of the ultrasonic cavitation bubbles.