Numerical investigation of surface tension effects on 2-D cavities near a solid wall
N表面张力对近固壁二空化泡影响的数值研究

When the effect of buoyancy force is neglected,surface tension effect on the axisymmetric growthand collapse of two cavities near and above a solid wall is investigated numerically by boundary integral method.It is found that when the maximal equivalence radius of the lower cavity is half of that of the upper one,surfacetension effect may cause the lower cavity collapse faster and its downward liquid jet stronger and wider if theBjerknes force of the wall to the lower cavity is larger than that of the upper cavity.And surface tension maycause the lower cavity collapse slower and its upward jet weaker,thinner and longer if the Bjerknes force of theupper cavity to the lower one is larger than that of the wall.In particular,surface tension may have substantialeffect on the collapse of the lower cavity such as change the direction or the form of the jet(from annular todownward or from upward to annular)if the two Bjerknes forces of the wall and the upper cavity to the lowercavity are nearly equal.When the upper cavity is equal to or smaller than the lower one,surface tension hasno significant effect on the behavior of the two cavities.The mechanism of surface tension effect is analyzedqualitatively.