Numerical modeling of ultrasonic cavitation by dividing coated microbubbles into groups

Yanghui Ye; Yangyang Liang; Cong Dong; Zhongming Bu; Guoneng Li; Youqu Zheng

doi:10.1016/j.ultsonch.2021.105736

Numerical modeling of ultrasonic cavitation by dividing coated microbubbles into groups

Ultrason Sonochem. 2021 Oct:78:105736. doi: 10.1016/j.ultsonch.2021.105736. Epub 2021 Aug 26.

Authors

Yanghui Ye¹, Yangyang Liang², Cong Dong¹, Zhongming Bu¹, Guoneng Li¹, Youqu Zheng¹

Affiliations

¹ Department of Energy and Environment System Engineering, Zhejiang University of Science and Technology, Hangzhou 310023, China.
² College of Mechanical Engineering, Zhejiang University of Technology, Hangzhou, China. Electronic address: liangyy@zjut.edu.cn.

Abstract

Homogeneous cavitation models usually use an average radius to predict the dynamics of all bubbles. However, bubbles with different sizes may have quite different dynamic characteristics. In this study, the bubbles are divided into several groups by size, and the volume-weighted average radius is used to separately calculate the dynamics of each group using a modified bubble dynamics equation. In the validation part, the oscillations of bubbles with two sizes are simulated by dividing them into 2 groups. Comparing with the predictions by the Volume of Fluid (VOF) method, the bubble dynamics of each size are precisely predicted by the proposed model. Then coated microbubbles with numerous sizes are divided into several groups in equal quantity, and the influence of the group number is analyzed. For bubble oscillations at f = 0.1 MHz and 1 MHz without ruptures, the oscillation amplitude is obviously under-estimated by the 1-group model, while they are close to each other after the group number increases to 9. For bubble ruptures triggered by Gaussian pulses, the predictions are close to each other when more than 5 groups are used.

Keywords: Coated microbubble; Grouping; Homogeneous model; Ultrasonic cavitation.