SPH方法与LBM方法在溃坝水流模拟中的对比研究  

A Comparative Study of SPH and LBM Methods for Numerical Simulation of Dam-break Flow

作　　者：张力方 张建民[1] ZHANG Li-fang;ZHANG Jian-min(State Key Laboratory of Hydraulics and Mountain River Engineering,Sichuan University,Chengdu 610065,China)

机构地区：[1]四川大学水力学与山区河流开发保护国家重点实验室,成都610065

出　　处：《中国农村水利水电》2020年第10期236-241,共6页China Rural Water and Hydropower

基　　金：国家自然科学基金面上项目(NO51879176)。

摘　　要：光滑粒子流体动力学(SPH)和格子玻尔兹曼方法(LBM)作为两种新兴的数值模拟手段,均能精确地捕捉带有自由面剧烈变形的流体问题。SPH法和LBM法分别被应用于模拟二维溃坝、三维溃坝水流碰撞固定障碍物以及可运动障碍物,并与试验监测数据对比分析得出,SPH方法得到的自由面更加光滑、清晰,但会有个别粒子附着在壁面,压力值预测会出现波动,说明对于动量方程的黏性项和固壁边界条件需要进一步改善,与离散单元法(DEM)耦合能够准确模拟可运动障碍物的位移;LBM方法得到的自由面在大变形处较为凌乱、破碎,对于水位、压力的预测比较准确,但是对于刚体运动的模拟还需加强。此外,还对比了两种方法的计算效率,在相同CPU的条件下,LBM计算效率高于SPH方法,GPU并行能够极大缩短计算时间。Smooth Particle Hydrodynamics(SPH)and Lattice Boltzmann Method(LBM)can accurately capture the violent deformation of free surface as novel numerical simulation methods.SPH and LBM methods are applied to simulate the 2-D dam-break flow,the 3-D dam-break flow striking fixed and transportable obstacles.Compared with previous flume data,SPH method can get smoother and clearer free surface,but some particles adhere to the boundary wall and the predicted pressure values fluctuate at times.The viscous term of momentum equation and boundary conditions need to be improved further.Coupled with the discrete element method(DEM),SPH method can resolve solid-fluid interactions.The free surface obtained by LBM method is splashing and broken at large deformation,and the prediction of water depth and pressure is more precise,but the simulation of rigid body motion needs to be strengthened.In addition,the computational efficiency of the two methods is also compared.Under the same CPU scenario,the computational efficiency of LBM is higher than that of SPH method.GPU parallelism can greatly reduce computing time.

关 键 词：溃坝水流 SPH方法 LBM方法 自由面 数值模拟 

分 类 号：TV1224[水利工程—水文学及水资源]