微可压缩SPH流体的稳定性固体边界处理算法  

Stable Solid Boundary Handling Algorithm of Weakly Compressible SPH Fluids

作　　者：邵绪强[1] 周忠[1] 张劲松[1] 吴威[1] 

机构地区：[1]北京航空航天大学虚拟现实技术与系统国家重点实验室,北京100191

出　　处：《计算机辅助设计与图形学学报》2014年第11期1915-1922,1929,共9页Journal of Computer-Aided Design & Computer Graphics

基　　金：国家"八六三"高技术研究发展计划(2012AA011801)

摘　　要：固流耦合,即流体的固体边界处理一直是基于物理的流体模拟技术的研究重点.为解决SPH流体模拟中固流耦合存在的交界面处流体粒子衰减和穿透问题,提出一种固体采样边界粒子与动量守恒保持的位置-速度修正方案相结合的固流耦合方法.首先在预处理阶段对快速格子形状匹配(fast lattice shape matching,FLSM)模型表示的固体边界进行表面和内部边界粒子采样;然后在运行过程中计算流体粒子密度和受力时考虑边界固体粒子的相对贡献;最后利用动量守恒保持的位置-速度修正方案对流体粒子进行位置和速度的修正.为了提高计算速度以满足交互式应用需求,把每个迭代步长内的计算完全并行化后加载到GPU上进行加速处理.实验结果表明,该算法实现了微可压缩SPH流体与刚体以及弹性体的双向耦合,并可以高效、稳定地模拟固流耦合中的非穿透、液滴飞溅、溶解等复杂现象.Fluid‐solid coupling ,namely solid boundary handling ,has been an important research topic in physically based fluid animation .In this paper ,we propose a novel stable and fast solid boundary handling algorithm for weakly compressible smoothed particle hydrodynamics （WCSPH ） .First ,we sample the deformable solids with inner and surface boundary particles in preprocessing stage .Then we compute the relative contributions of boundary particles to their neighboring fluid particles during the density and force computation of SPH fluids .Finally ,in order to prevent the penetration artifacts near the fluid‐solid interfaces simultaneously , we employ a momentum‐conserving velocity‐position correction scheme to adjust the velocities and positions of fluid particles w hose distances to solid boundaries are smaller than a certain threshold .For improving the efficiency ,we entirely implement the unified particle framework on GPUs using CUDA to accelerate the computation of each time step . The results show that the proposed method can handle the stable two‐way coupling of WCSPH fluids and deformable solids modeled by fast lattice shape matching （FLSM ） , and simulate complex phenomena in the coupling ,such as non‐penetrations ,splashes and melting .

关 键 词：固流耦合 流体模拟 并行计算 拉格朗日粒子模型 形状匹配 

分 类 号：TP391.41[自动化与计算机技术—计算机应用技术]