A Numerical and Experimental Study of Wall Pressure Caused by an Underwater Explosion Bubble
A Numerical and Experimental Study of Wall Pressure Caused by an Underwater Explosion Bubble
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水下爆炸气泡引起的壁压力的数值和实验研究
DOI：
10.1155/2018/6139510
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发表时间：
2018-01-01
影响因子：
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通讯作者：
Cui, Xiongwei
中科院分区：
文献类型：
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作者：
Chen, Yingyu;Yao, Xiongliang;Cui, Xiongwei
通过实验方法和数值研究对气泡的动力学行为和壁面中心压力进行了研究。实验采用高速摄像机捕捉刚性壁面下水下爆炸气泡的动态过程，并利用压力传感器测量壁面中心的压力。为了揭示刚性壁面第一次气泡崩塌时的压力过程和机理，采用边界元法（BIM）进行数值研究。两种不同暂态参数（γ=0.38和γ=0.90）的数值结果与实验测量和观测结果非常吻合。根据实验结果和数值计算结果，可以得出第一个峰值是由重入式射流撞击引起的，随后的飞溅效应扩大了第一个射流撞击的持续时间。当γ=0.38时，溅射射流对最小体积气泡产生强烈的冲击，由于周围高压的作用，产生了许多细小的气泡，形成了气泡环状，并迅速坍塌，发出多重激波。当γ=0.90时，气泡周围的压力场足够低，只出现一个微弱的反弹气泡峰。
The bubble dynamics behaviors and the pressure in the wall center are investigated through experimental method and numerical study. In the experiment, the dynamics of an underwater explosion (UNDEX) bubble beneath a rigid wall are captured by high-speed camera and the wall pressure in the wall center is measured by pressure transducer. To reveal the process and mechanism of the pressure on a rigid wall during the first bubble collapse, numerical studies based on boundary element method (BIM) are applied. Numerical results with two different stand-off parameters (γ=0.38 and γ=0.90) show excellent agreement with experiment measurements and observations. According to the experimental and the numerical results, we can conclude that the first peak is caused by the reentrant jet impact and the following splashing effect enlarged the duration of the first jet impact. When γ=0.38, the splashing jet has a strong impact on the minimum volume bubble, a number of tiny bubbles, formed like bubble ring, are created and collapse more rapidly owing to the surrounding high pressure and emit multi shock waves. When γ=0.90, the pressure field around the bubble is low enough only a weak rebounding bubble peak occurs.