自激振荡射流空化泡动力学特征及超声强化数值研究

Numerical Study on the Dynamic Characteristics and Ultrasonic Enhancement of Cavitation Bubbles under Self-Excited Oscillating Jet

王满 袁淼 闵瑞 袁涛

WANG Man YUAN Miao MIN Rui YUAN Tao

炼焦煤资源绿色开发全国重点实验室, 河南平顶山 467000 武汉大学动力与机械学院, 湖北武汉 430072 河南省瓦斯地质与瓦斯治理重点实验室（河南理工大学）, 河南焦作 454000

State Key Laboratory of Coking Coal Resources Green Exploitation, Pingdingshan, Henan, 467000, China School of Power and Mechanical Engineering, Wuhan University, Wuhan, Hubei, 430072, China State Key Laboratory Cultivation Base for Gas Geology and Gas Control, Henan Polytechnic University, Jiaozuo, Henan, 454000, China

为了解亥姆霍兹喷嘴腔内空化泡动力学特征及超声波作用下空化泡的响应演化规律，以空化动力学为基础，建立了自激振荡喷嘴腔内空化气泡动态变化的计算模型，研究了亥姆霍兹喷嘴腔长和腔径对腔内空化强度的影响及附加声场情况下空化泡的动态变化规律。研究结果表明：自激振荡射流喷嘴的腔长和腔径均会影响腔室内空化强度，腔长和腔径增大有利于提高空化强度；声–流耦合场中的空化泡膨胀收缩相比单一流场更剧烈；超声波的频率和幅值对于空化强度的影响较大，存在最佳的超声波频率，使腔内空化强度达到最大，超声频率过高会导致声波膨胀时间缩短，空化核的增长时间也会随之缩短；声场幅值与空化强度正相关。研究结果有助于提升自激振荡空化射流技术及超声增强脉冲射流技术的现场应用效果。

In order to understand the dynamic characteristics of cavitation bubbles in a Helmholtz nozzle cavity and the evolution of cavitation bubble responses under the influence of ultrasonic waves, a mathematical model describing the dynamic variation of cavitation bubbles in a self-excited oscillating nozzle cavity was developed based on cavitation dynamics. In addition, the effects of Helmholtz nozzle cavity length and diameter on cavitation intensity and the dynamic behavior of cavitation bubbles when subjected to an additional acoustic field were studied. The results showed that both the cavity length and cavity diameter of the self-oscillating jet nozzle affected the cavitation intensity in the cavity. The increase in the cavity length and cavity diameter contributed to improving cavitation intensity. The expansion and contraction of cavitation bubbles in the acoustic–fluid coupling field were more severe than those in a single flow field. The frequency and amplitude of ultrasonic waves also had a great influence on cavitation intensity, with an optimal ultrasonic wave frequency identified for maximizing cavitation intensity in the cavity. In addition, excessively high ultrasound frequencies resulted in shorter acoustic wave expansion time and a shorter growth time of the cavitation nucleus. There was a positive association between cavitation intensity and acoustic field amplitude. These research findings are valuable for enhancing the practical application of self-excited oscillating cavitation jet technology and ultrasonic-enhanced pulse jet technology.

国家自然科学基金面上项目“非淹没双空化磨料射流发生调制机理与冲击破坏特性研究”（编号：52175245）资助。

https://doi.org/10.11911/syztjs.2023058