Nonlinear interaction between gas bubble and free surface
Nonlinear interaction between gas bubble and free surface
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DOI：
10.1016/0045-7930(96)00007-2
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发表时间：
1996-09
影响因子：
2.8
通讯作者：
Q. Wang;K. Yeo;B. Khoo;K. Lam
中科院分区：
文献类型：
--
作者：
Q. Wang;K. Yeo;B. Khoo;K. Lam
对气泡在自由表面附近的非线性演化进行了数值研究。流动被假定为潜在的和边界积分方法被用来解决速度势的拉普拉斯方程。气泡含量由绝热气体定律描述。对于一个气泡开始在1.5最大气泡半径从静止的自由表面，三个崩溃模式已被注意到：一个向下指向的Bjerknes射流的情况下，弱浮力;一个向上指向的浮力射流的情况下，强浮力;和中间的情况下，与近零开尔文脉冲状态的气泡假设在崩溃过程中没有喷射扁圆形。虽然对于不同的浮力参数δ值，气泡的演化模式可能不同，但气泡体积随时间的变化似乎在很大程度上与δ无关。当气泡在距离自由表面小于1.0RRm处开始时，在崩溃阶段形成更高的自由表面尖峰。根据浮力的不同，气泡仍然有三种崩溃模式。对环形气泡的演化过程也进行了模拟和研究。最后，结果示出描绘的效果的初始“压力”上的气泡附近的自由表面的演变。
The nonlinear evolution of gas bubbles in the vicinity of a free surface is investigated numerically. The flow is assumed to be potential and a boundary-integral method is used to solve the Laplace equation for the velocity potential. The bubble content is described by an adiabatic gas law. For a bubble initiated at 1.5 maximum bubble radius from the quiescent free surface, three collapse patterns have been noticed: a downward directed Bjerknes jet for the case of weak buoyancy force; an upward directed buoyancy jet for the case of strong buoyancy force; and for the intermediate case with near-null Kelvin impulse state the bubble assumes an oblate form during collapse with no jetting. While the evolution patterns of a bubble may be different for different values of the buoyancy parameter δ, the variation of the bubble volume with time appears to be largely independent of δ. When the bubble is initiated at and less than 1.0RRmfrom the free surface, a much higher free surface spike is formed during the collapse phase. There are still three collapse patterns for the bubble depending on the buoyancy force imposed. The evolution of the bubbles in toroidal form is also simulated and examined. Finally, results are shown depicting the effect of initial ‘pressure’ on the evolution of the gas bubble near to the free surface.