近自由面水下爆炸气泡相似问题的仿真研究

Numerical Study of Similarity of Bubbles Induced by UNDEX near Free Surface

为更好地了解近自由面水下爆炸气泡运动的相似问题,以便可以利用相对廉价的缩比试验得到原型试验才能得到的信息,在不可压缩非粘性流体中守恒方程相似的基础上,考虑气泡的最大半径、炸药深度、压力等参数相似,提出了一种水下爆炸气泡运动的相似设计方法,并通过数值仿真的方法进行了验证。同时,对近自由面气泡射流产生的条件和特点进行了分析。结果表明,在满足相似条件的工况下,气泡的运动和气泡射流产生的方向、形状等特性都基本上相同。

The study is an attempt to better understand the similarity of the bubble phenomena induced by underwater explosion near the free surface. The motivation is to be able to use relatively inexpensive small-scale tests to obtain the same information produced by expensive full-scale tests. On the base of the scaling of conservation equations for incompressible inviscid fluid, a similarity criterion for bubble phenomena was proposed by use of the similarity of the maximum radius, the depth of the charge and the pressure. It was tested by the numerical simulation. And the conditions and characters of the jets from collapsing bubbles were also analyzed. The results show that the movement of the bubble, the direction and shape of the jet are same if the conditions satisfy the similarity criteria.