水滴撞击球面形态与压力的数值模拟

Morphology and pressure simulation of water droplet impinging on a spherical surface

通过建立三维数学模型,采用有限体积(Volume of Fluid,VOF)耦合界面追踪法(Level-Set)的两相流界面追踪法(Coupled Level-Set and Volume of Fluid,CLSVOF),模拟We=266的水滴撞击干燥球面,对撞击后的水滴形态以及内部压力进行分析。研究结果表明,水滴撞击球面经历了铺展-回缩-附着的过程。当水滴撞击到球面0.1ms后,最大压力从液膜最外侧逐渐向液膜中心移动;当液膜产生“冠指”时,最大压力再次转移到液膜最外侧;在回缩过程中,最大压力所处的位置逐渐向液膜中心移动,并在30.0ms时,再次回到液膜中心。此后,最大压力的相对位置保持不变,持续到稳定状态。

The CLSVOF method of Volume of Fluid(VOF)coupled with Level-Set method is used to simulate the impact of water droplets with We=266on the dry sphere in terms of a three-dimensional model.The morphology of droplet after impinging along with its pressure was investigated.The results show that when water droplets impact on a sphere,including aprocess of spreading,retraction and attachment.When the droplet hits on the sphere at 0.1ms,maximum pressure gradually moves from the outermost part of liquid film to the center of liquid film.When"crown finger"of liquid film is generated,its maximum pressure shifts to outermost part of the liquid film again.During the retraction stage,the position of the maximum pressure gradually moves towards the center of the liquid film and finally reaches to the center angina at 30.0ms.After that,the relative position of the maximum pressure remains unchanged until the steady state.