摘要
针对大场景下流体仿真计算复杂度高的问题,本文以浅水方程为基础,提出一种改进的二维光滑粒子方法.该方法中使用光滑粒子法离散二维浅水方程,将水深作为粒子的属性,把计算复杂度降到二维的程度;同时为了提高邻域粒子的搜索效率,提出一种基于动态网格的邻近粒子搜索方法;并使用虚粒子和惩罚力相结合的方法处理边界条件以高效率应对复杂边界;渲染时,首先将粒子映射并插值到规则网格内得到流体表面,避免三维流体表面重构复杂度高的问题,最后利用OpenGL着色语言实现加速渲染,从而达到大场景下流体实时仿真.
Smoothed particle hydrodynamics（SPH） method is a kind of meshless method,which is used to solve the problem of fluid simulation without complex operations of the grids.To reduce the computational complexity,SPH method based on the two-dimensional shallow water equations is employed to establish a fluid model.In large scale scenes,taking into account the high computational complexity and the serious distortion problems,in this paper we introduce an improved two-dimensional SPH algorithm according to the shallow water equations.The proposed method with two-dimensional complexity is obtained by discretizing the two-dimensional shallow water equations with SPH,and the depth of water is introduced as the particle＇s property.The problem of increased amount of calculation cannot be well solved by using traditional neighboring particle search method based on tree structure.To improve the efficiency of search and simplify the search operation of neighborhood particles,in this paper we introduce a point-in-box search algorithm and put forward a neighboring particles searching method on the basis of dynamic grid.Besides,for large scale scenes,by considering that the virtual particle method provides slow computation speed with complex boundary condition,the type-one virtual particles are utilized to ensure that the borders can be calculated precisely by combining the punish force to prevent the phenomenon of particle boundary penetrating.Therefore,a method is further obtained to handle boundary condition efficiently by combining the virtual particles with punish force in this paper.In the process of rendering,the fluid surface is first determined by mapping and interpolating particles into regular grids without the complex reconstruction of surface in three-dimensional.Then,we utilize the bilinear interpolation method to deal with the problem of missing values,and the surface grids are further densified.With Open Scene Graph three-dimensional render engine,Open GL Shading Language is adopted to speed up the rendering speed,and in this way,the real-time fluid simulation of large scale scenes can be further achieved.With the basic KD tree searching method employed in the simulations,the comparative experiments are provided to verify effectiveness of the proposed searching method based on dynamic grid.Given the data set obtained from random points,experimental results demonstrate that the method in this paper can be used to solve the problem of neighboring particles searching in large scale scenes.To show the effectiveness of the proposed method on the basis of the virtual particles and the punish force,another experiment based on the collapsing of a water column is further provided.Besides,in this paper we conduct an experiment on a certain actual reservoir terrain to prove that the proposed method can be applied to fluid simulation of large scale scenes.
作者
张海超
郑丹晨
边茂松
韩敏
Zhang Hai-Chao Zheng Dan-Chen Bian Mao-Song Han Min(Faculty of Electronic Information and Electrical Engineering, Dalian University of Technology, Dalian 116023, China)
出处
《物理学报》
SCIE
EI
CAS
CSCD
北大核心
2016年第24期105-112,共8页
Acta Physica Sinica
基金
国家自然科学基金(批准号:61374154)资助的课题~~
关键词
光滑粒子法
浅水方程
流体仿真
三维模拟
smoothed particle hydrodynamics
shallow water equations
fluid simulation
three-dimensional simulation
