Improved assessment sensitivity of time-varying cavitation events based on wavelet analysis

Qi Zhang; Guofeng Zhang; Lan Luo; Zijun Liu; Yifei Zhu; Zheng Fan; Xiasheng Guo; Xiaoge Wu; Dong Zhang; Juan Tu

doi:10.1016/j.ultras.2023.107227

Improved assessment sensitivity of time-varying cavitation events based on wavelet analysis

Ultrasonics. 2024 Mar:138:107227. doi: 10.1016/j.ultras.2023.107227. Epub 2023 Dec 15.

Authors

Qi Zhang¹, Guofeng Zhang¹, Lan Luo¹, Zijun Liu¹, Yifei Zhu¹, Zheng Fan², Xiasheng Guo¹, Xiaoge Wu³, Dong Zhang⁴, Juan Tu⁵

Affiliations

¹ Key Laboratory of Modern Acoustics (MOE), Department of Physics, Collaborative Innovation Center of Advanced Microstructure, Nanjing University, Nanjing 210093, China.
² School of Mechanical and Aerospace Engineering, Nanyang Technological University, Singapore 639798, Singapore.
³ Environment Science and Engineering College, Yangzhou University, Yangzhou 225009, Jiangsu, China. Electronic address: xgwu@yzu.edu.cn.
⁴ Key Laboratory of Modern Acoustics (MOE), Department of Physics, Collaborative Innovation Center of Advanced Microstructure, Nanjing University, Nanjing 210093, China. Electronic address: dzhang@nju.edu.cn.
⁵ Key Laboratory of Modern Acoustics (MOE), Department of Physics, Collaborative Innovation Center of Advanced Microstructure, Nanjing University, Nanjing 210093, China; The State Key Laboratory of Acoustics, Chinese Academy of Science, Beijing 100080, China. Electronic address: juantu@nju.edu.cn.

PMID: 38118237
DOI: 10.1016/j.ultras.2023.107227

Abstract

Ultrasonic cavitation, characterized by the oscillation or abrupt collapse of cavitation nuclei in response to ultrasound stimulation, plays a significant role in various applications within both industrial and biomedical sectors. In particular, inertial cavitation (IC) has garnered considerable attention due to the resulting mechanical, chemical, and thermal effects. Passive cavitation detection (PCD) has emerged as a valuable technique for monitoring this procedure. While the fast Fourier transform (FFT) is a widely used algorithm to analyze IC-induced broadband noise detected by PCD system, it may not adequately capture the time-varying instability of cavitation due to potential nuclei collapse during ultrasound irradiation. In contrast, the continuous wavelet transform offers a more flexible approach, enabling more sensitive analysis of signals with varying frequencies over time. In this study, nanodiamond (ND) and its derivative, nitro-doped nanodiamond (N-AND), known to possess cavitation potential from previous research, were chosen as the source of cavitation nuclei. The cavitation signals detected by PCD were subjected to both FFT and wavelet analyses, with their results comprehensively compared. This research showcased the feasibility of employing wavelet analysis for effective inertial cavitation evaluation. It provided the advantage of monitoring the temporal evolution of cavitation events in real-time, enhancing sensitivity to weak and unstable cavitation signals, especially those in higher order components (3rd and 4th order). Additionally, it yielded a higher level of precision in determining IC thresholds and doses. Furthermore, the inclusion of time information through wavelet analysis offered insights into the limitations of low-cycle ultrasound in inducing IC. This study introduces a novel perspective for more sensitive and precise cavitation assessment, leveraging time and frequency data from wavelet analysis, and holds promise for effective utilization of cavitation effects while minimizing losses and damages resulting from unintended cavitation events.

Keywords: Fourier analysis; Inertial cavitation; Nitrogen doped nanodiamond; Passive cavitation detection; Wavelet analysis.