中文摘要：

本文对传统的光滑粒子动力学方法进行了改进．改进的光滑粒子动力学方法对传统粒子方法中的核梯度进行了修正，采用了一种新型的耦合边界条件，添加了表面张力和人工应力的计算程序．应用改进的光滑粒子动力学方法对液滴冲击液膜问题进行了数值模拟．得到了不同时刻液滴内部的压力变化特征，精细地捕捉了不同时刻的自由面，从机理上分析了液滴产生飞溅的条件，探讨了韦伯数，表面张力对液滴冲击液膜问题的影响．计算结果表明，改进光滑粒子动力学方法能够有效地描述液滴冲击液膜的动力学特性和自由表面变化特征，能够得到稳定精度的结果．

英文摘要：

In this paper, we present a modified smoothed particle hydrodynamics （SPH） method. In order to well predict the morphology change of liquid drop, the presented SPH method employs a kernel gradient correction and a coupled solid boundary treatment algo- rithm. An inter-particle interaction force is used to model surface tension, and an artificial stress model is used to deal with tensile instability. The process of droplet impacting on liquid film is numerically simulated by the modified SPH method, which can well predict the pressure field evolution process of the drop impacting onto the liquid film and capture the variation of the free surface at dif- ferent instants. Effects of Web number and surface stress on droplet impacting are also investigated, and mechanism of droplet splashing is analyzed. It is clearly demonstrated that the modified SPH method can effectively describe the dynamics of droplet splashing and the variation of the free surface. The obtained liquid drop morphology accords well with the results from other sources.