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题名	瞬态单一声空化气泡的动力学过程及空化发光
作者	吴先梅
学位类别	博士
答辩日期	2003
授予单位	中国科学院声学研究所物理学
授予地点	中国科学院声学研究所物理学
其他题名	The dynamic process and cavitation luminescence of transient single acoustic cavitation bubbles
中文摘要	本报告主要研究了瞬态单一声空化气泡的产生和长消过程、发光效应，并结合实验，应用Rayleigh一Plesset方程模拟了在力学负脉冲作用下空化气泡的动力学过程。实验中选择了丙酮、酒精、蒸馏水、甘油和硅油五种不同的液体作为研究的对象，比较了不同液体中声空化气泡的运动过程及其发光效应。应用高速CCD和玻璃管底的压电片研究了气泡的运动过程和液体中的声场。结果发现，声空化气泡都是从所测得液体中压力信号的一个小负压处开始生长，到达厘米级最大半径后开始收缩直至崩溃，崩溃时产生很强的冲击波。分析认为，在玻璃管被突然制动时，管内液体在管底产生了一个较强的拉伸脉冲波，使得预先"种植"的气泡核生长、压缩和崩溃。五种不同的液体中空化气泡的运动各具特色。其中丙酮和酒精中空化气泡的行为很相似，水和它们略有不同，硅油和甘油则很接近。对五种液体中空化气泡的发光研究发现，其崩溃时发光强度由弱到强的顺序为：丙酮、酒精、蒸馏水、甘油、硅油，与其蒸汽压由大到小的排列顺序表现为一致。还发现，液柱高度与发光强度有一定的关系；瞬态单一空化气泡的发光强度比稳态单一空化气泡的发光强度一般约高一个数量级；甘油水溶液中空化气泡的发光强度随着甘油的浓度增加而有明显地增加。实验中还发现，气泡在刚开始生长时有过去未见报道过的微弱发光。．为了分析压力信号与气泡运动变化二者间关系，我们应用Royleigh一Plesset方程模拟了在力学负脉冲作用下在几种不同的液体、气泡或负压脉冲参数时空化气泡的动力学过程。在对不同液体进行计算时发现，丙酮和酒精的计算结果几乎完全相同，水与它们有一些不同，硅油和甘油的结果比较接近，而和前三种有较大差异。计算还发现，初始半径R。、压力负脉冲的幅度对气泡的运动变化有着很显著的影响，压力负脉冲的宽度及其下降沿和上升沿的斜率也会对R－－t曲线产生一定的影响，但是其影响较小。所得计算结果还很粗略。尽管如此计算结果对理解实验中的一些现象可以起到一些启发作用。
英文摘要	This report studies the generation, growth and collapse of transient single cavitation bubbles and also their luminescence. In conjunction with the experimental results, the dynamic process of the cavitation bubbles under a tension pulse is simulated by the use of the Rayleigh-Plesset equation. We choose, for the comparison of the differences in these effects, five different liquids: acetone, alcohol, water, glycerin and silicon oil. In our experiments, the dynamics of the cavitation bubbles and a high speed CCD and a piezoelectric transducer record the sound fields in the liquids respectively and simultaneously. It is found that the acoustic cavitation bubble begins to grow when a negative pressure pulse appears in the pressure signal of the sound field. After reaching usually very large maximum size (of the order of centimeter in radius), the bubble begins to shrink until it collapses when a strong shock is generated. After analyzing the sound fields signal, we conclude that during the sudden arrest of the glass tube, a tension wave is produced in the water column, starting from the tube bottom and traveling upwards, which makes the bubble nucleus grow, shrink and then collapse. The dynamic processes of the cavitation bubbles in five liquids are not the same. The behaviors of the cavitation bubbles in acetone and alcohol are very similar while that of- the bubbles in water is- slightly different. The behaviors of the cavitation bubbles in silicon oil and glycerin differ even more, but are similar between themselves. Our studies on the luminescence during bubbles' collapse show that the order of the luminescence intensity from weak to strong is as follows: acetone, alcohol, water, glycerin and silicon oil, which order is in agreement with the order of the vapor pressure of the liquids from strong to weak. It is also found that: 1) The luminescence intensity is related to the height of the liquid column; 2) The luminescence intensity of the transient single cavitation bubbles is about an order of magnitude higher than that of the continuous single bubble sonoluminescence; 3) The luminescence intensity of our cavitation bubbles in glycerin-water mixtures goes up as the glycerin concentration increases. Additionally, we find that there is weak luminescence when the bubble just begins to grow; this, as far as we are aware, is a phenomenon, not reported before. In order to analyze the relationship between the pressure signal and the bubble dynamics, we simulate the dynamic process of the cavitation bubble under the tension pulse with various parameters. Our computation for different liquids shows that the R-t curves of acetone and alcohol are almost the same, and are slightly different from that of water. The R-t curves of silicon oil and glycerin are very similar, but are much different from those of the foregoing three liquids. It is also found that the width as well as the slopes of the rising and the trailing edges of the tension pulse has some effects on the R-t curve. The computations are preliminary, but it may enlighten the understanding of some phenomena observed in our experiments.
语种	中文
公开日期	2011-05-07
页码	53
内容类型	学位论文
源URL	[http://159.226.59.140/handle/311008/1024]
专题	声学研究所_声学所博硕士学位论文_1981-2009博硕士学位论文
推荐引用方式 GB/T 7714	吴先梅. 瞬态单一声空化气泡的动力学过程及空化发光[D]. 中国科学院声学研究所物理学. 中国科学院声学研究所物理学. 2003.

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