Experimental Study on the Impact Characteristics of Cavitation Bubble Collapse on a Wall
Experimental Study on the Impact Characteristics of Cavitation Bubble Collapse on a Wall
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DOI：
10.3390/w10091262
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发表时间：
2018-09-01
期刊：
影响因子：
3.4
通讯作者：
Zhang, Qi
中科院分区：
文献类型：
--
作者：
Luo, Jing;Xu, Weilin;Zhang, Qi
空化现象作为一种水动力现象，在水利、化工、医疗等诸多行业中受到广泛关注。对空化泡的产生、发展和溃灭的研究较多，但对空化泡溃灭对壁面循环冲击强度变化的研究较少。本文采用高速动态采集与分析系统和压力测量系统相结合的方法，研究了在壁面附近产生的空化泡在不同距离下对壁面的影响。结果表明：(1)以壁面所承受的冲击压力为判别标准，得到了空化泡在破碎过程中产生微射流的临界条件，因此，空化泡在壁面附近的破碎主要分为一次冲击区破碎、二次冲击区破碎和缓释区破碎；(2)由空化泡崩落对壁面的冲击强度可以看出，第一次崩落时空化泡对壁面的冲击随着（空化泡与壁面的无因次距离）的增大而减小，但第二次崩落对壁面的冲击先增大后急剧减小。小于1.33时，对壁面的冲击主要来自第一次坍塌。在1.33 ~ 2.37之间时，对壁面的冲击主要来自二次塌陷。这些结论对空化侵蚀的利用或防治技术具有潜在的理论价值。
As a hydrodynamic phenomenon, cavitation is a main concern in many industries such as water conservancy, the chemical industry and medical care. There are many studies on the generation, development and collapse of cavitation bubbles, but there are few studies on the variation of the cyclic impact strength on walls from the collapse of cavitation bubbles. In this paper, a high-speed dynamic acquisition and analysis system and a pressure measuring system are combined to study the impact of a cavitation bubble generated near a wall for various distances between the cavitation bubble and the wall. The results show that (1) with the discriminating criteria of the impact pressure borne by the wall, the critical conditions for the generation of a micro-jet in the collapse process of the cavitation bubbles are obtained, and therefore collapses of cavitation bubbles near the wall are mainly divided into primary impact area collapses, secondary impact area collapses and slow release area collapses; (2) it can be seen from the impact strength of the cavitation bubble collapse on the wall surface that the impact of cavitation bubbles on the wall surface during the first collapse decreases as (the dimensionless distance between the cavitation bubble and the wall) increases, but the impact of the second collapse on the wall surface increases first and then decreases sharply. When is less than 1.33, the impact on the wall surface is mainly from the first collapse. When is between 1.33 and 2.37, the impact on the wall surface is mainly from the second collapse. These conclusions have potential theoretical value for the utilization or prevention and control technologies for cavitation erosion.