Dai Chenwei, Chen Xingwang, Miao Qing, Yin Zhen, Zhang Ming, Chen Jiajia
School of Mechanical Engineering, Suzhou University of Science and Technology, Suzhou 215009, PR China.
School of Mechanical Engineering, Suzhou University of Science and Technology, Suzhou 215009, PR China.
Ultrasonics. 2026 Mar;159:107851. doi: 10.1016/j.ultras.2025.107851. Epub 2025 Oct 8.
Ultrasonic cavitation has garnered extensive attention for its potential in surface modification due to its characteristics such as microjet impingement and high-pressure shockwaves generated during bubble collapse. Although the collapse dynamics of a single bubble have been widely examined, researches on the global fluid behavior remains insufficient. This study establishes a numerical model of ultrasonic cavitation with the aim of systematically examining how ultrasonic amplitude, ultrasonic frequency and standoff distance affect the bubble distribution and the absolute pressure in the fluid domain. On this basis, experiments were also conducted using a self-developed ultrasonic vibration device to investigate the cavitation erosion on aluminum alloy by measuring the surface morphology and roughness. The results show that the cavitation bubbles are primarily distributed within 0.7 mm beneath the tool end, reaching a peak absolute pressure of 4.22 MPa when the standoff distance is 1 mm. When the ultrasonic amplitude is increased, the peak absolute pressure is enlarged from 0.74 MPa to 3.53 MPa, the peak vapor volume fraction is increased from 6.5 % to 34.8 %, and the surface roughness of eroded workpiece is raised from 0.110 μm to 1.013 μm, with surface morphology evolving from microscopic pits to large-scale material removal. The vapor volume fraction reaches the maximum value of 97 % at a standoff distance of 0.25 mm, but sharply decreases to 0.08 % at 2 mm. The workpiece is most severely eroded to the largest roughness of 1.013 μm at the standoff distance of 0.5 mm. When the ultrasonic frequency is brought up, the peak absolute pressure is progressively increased, but the peak vapor volume fraction is diminished with accelerated change rate. Low-frequency ultrasonic vibration produces stronger impacts by fewer large bubbles, whereas high-frequency ultrasonic vibration generates weaker impacts by numerous small bubbles. The simulation and experimental results demonstrate strong agreement with each other, which provides deeper insights into the erosion mechanisms induced by ultrasonic cavitation. This article will enrich the fundamental theory of ultrasonic cavitation and provides theoretical support and guidance for material modification using ultrasonic cavitation.
超声空化因其在表面改性方面的潜力而备受关注，这是由于其具有微射流冲击和气泡崩溃过程中产生的高压冲击波等特性。尽管单个气泡的崩溃动力学已得到广泛研究，但对整体流体行为的研究仍显不足。本研究建立了超声空化的数值模型，旨在系统研究超声振幅、超声频率和间距如何影响流体域中的气泡分布和绝对压力。在此基础上，还使用自行开发的超声振动装置进行了实验，通过测量铝合金表面的形貌和粗糙度来研究其空蚀情况。结果表明，空化气泡主要分布在工具端部下方0.7毫米范围内，当间距为1毫米时，绝对压力峰值达到4.22兆帕。当超声振幅增加时，绝对压力峰值从0.74兆帕增大到3.53兆帕，蒸汽体积分数峰值从6.5%增加到34.8%，被侵蚀工件的表面粗糙度从0.110微米提高到1.013微米，表面形貌从微观凹坑演变为大规模材料去除。在间距为0.25毫米时，蒸汽体积分数达到最大值97%，但在2毫米时急剧降至0.08%。在间距为0.5毫米时，工件遭受的侵蚀最严重，粗糙度达到最大的1.013微米。当提高超声频率时，绝对压力峰值逐渐增加，但蒸汽体积分数峰值减小，且变化速率加快。低频超声振动由较少的大气泡产生更强的冲击，而高频超声振动由众多小气泡产生较弱的冲击。模拟和实验结果相互吻合，这为深入了解超声空化引起的侵蚀机制提供了更深刻的认识。本文将丰富超声空化的基础理论，并为利用超声空化进行材料改性提供理论支持和指导。
