基于SPH的雨滴打击不规则边界的模拟方法

SPH-Based Simulation of Raindrops Beating an Irregular Boundary

为实现对雨滴打击树枝等不规则边界过程的模拟,研究了流体粒子在网格表示的固体边界处的受力情况,提出了一种不需要粒子采样的边界受力模拟方法。采用高斯积分法则对网格模型的三角面片进行积分,并就此对固液边界的粒子的密度进行修正,以积分的方法对固体边界处的压力、粘性力等参数进行计算,从而保证边界粒子受力的连续性。同时,还提出了一种吸引力模型,用来控制粒子在沿着物体表面滑落时的运动。实验结果表明,该方法在模拟水滴铺展、收缩、沿着边界流动等现象时达到了较为真实的效果。

In order to simulate the process of raindrops hitting branches and other irregular boundary,research has been conducted on the force of the fluid particles on solid boundaries represented by the grid.A kind of boundary force simulation method without particle sampling is proposed.This approach exploits the Gauss quadrature rules to integrate the triangular patches of a mesh model and correct the particle density on the solid-liquid boundary.In addition,several parameters,including pressure and viscous forces on the solid-liquid boundary,are also calculated using an integral method to ensure the continuity of the boundary force and avoid a splashing phenomenon at the moment of particles’beating the boundary.Meanwhile,this paper propounds an attractive force model to control the movement of the boundary particles flowing down on the surface of an object.The experimental results reveal that the approaches proposed in this paper can achieve more realistic effects of phenomenon simulations,such as the raindrop spreading,retracting and flowing along the boundary,etc.