弱可压缩流体边界处理算法

针对流体与固体边界的交互模拟问题,提出一种基于弱可压缩光滑粒子流体动力学(SPH)的边界处理算法.首先,引入一种新的体积权重函数,解决固体边界非均匀采样区域流体密度的计算误差问题;然后,提出一种新的边界力计算模型,避免校正流体粒子位置信息,保证固体边界不可穿透;最后,提出一种改进的流体压力计算模型,保证流体的弱可压缩性.实验结果表明,所提算法可以有效地解决基于位置校正的边界处理方法在模拟弱可压缩流体与非均匀采样固体边界交互时存在的稳定性问题,且仅需边界粒子的位置信息,在节约内存的同时避免了位置校正所带来的额外计算开销.

Boundary handling algorithm for weakly compressible fluids

In order to simulate interactions of fluids with solid boundaries, a boundary handling algorithm based on weakly compressible Smoothed Particle Hydrodynamics (SPH) was presented. First, a novel volume-weighted function was introduced to solve the density estimation errors in non-uniformly sampled solid boundary regions. Then, a new boundary force computation model was proposed to avoid penetration without position correction of fluid particles. Last, an improved fluid pressure force model was proposed to enforce the weak incompressibility constraint. The experimental results show that the proposed method can effectively solve the stability problem of interactions of weakly compressible fluids and non-uniformly sampled solid boundaries using position correction-based boundary handling method. In addition, only the positions of boundary particles are needed, thus the memory as well as the extra computation due to position correction can be saved.