单个蒸汽气泡溃灭过程的边壁效应数值研究

Numerical Study of Boundary Effect During the Collapse of Single Vapor Bubble

采用数值模拟的手段,耦合流体体积(VOF)多相流模型和自然空泡模型,通过改变单个蒸汽气泡距竖直固壁和水面的距离,计算了这2类边壁共同作用下的溃灭过程.在溃灭的前期,气泡外形主要受水面边壁影响,呈远离水面向内凹陷的趋势;在溃灭的后期,固壁的影响凸显,凹陷的方向逐渐指向固壁.当气泡离固壁越近,溃灭时间越长;当气泡离水面越近时,溃灭时间越短.对固壁上的压力峰值,气泡距竖直固壁的距离起决定作用.

The collapse under the effect of the two kinds of boundaries was simulated by using the numerical method,coupling the volume of fluid multiphase method and cavitation model,and changing the distance from the single air bubble to the vertical wall and the surface of the water.In the earlier stage,the shape of bubble was mainly affected by the surface of the water and the upper surface of bubble was sunk.In the final stage,the influence of the wall became notable and the sunken direction pointed to the wall gradually.The closer the distance between the bubble and the wall,the shorter the collapse lasts.While the nearer the distance between the bubble and the surface of water,the longer the collapse continues.The distance between the bubble and the vertical wall determines the peak of pressure on the vertical wall.