摘要
流固边界处理一直是流体模拟的研究重点,边界力法和虚粒子法是研究流固边界的常用方法。边界力法通过对铺设在边界上的粒子施加排斥力防止粒子穿透,但边界力的计算限制了模拟速度。虚粒子法在边界处生成虚粒子,随着粒子数的增加所需的虚粒子数也随之增加,导致计算速度下降,且会出现流体与边界分离的现象。为此,提出一种对称区域边界处理方法,在保证逼真度的前提下满足实时性要求,随着粒子数的增加,其耗时增长也明显比其他传统方法慢,更适合对复杂场景的模拟,同时避免了边界处流体与边界分离的现象。CSF方法是处理表面张力常用的方法,可将表面张力看作体积力进行计算,大大减弱了表面形状对曲率计算的影响,而事实上曲率的计算只与表面的形状有关。为此,对CSF方法进行了改进,提出了一种基于表面粒子提取的表面张力计算方法,减小了传统CSF方法计算曲率的误差,提高了计算速度。模拟仿真的效果验证了该方法的有效性。
Flow-solid boundary processing has always been the focus of fluid simulation,and boundary force method and virtual particle methods are commonly used to study fluid-solid boundary.The boundary force method prevents particles from penetrating by applying repulsive forces to particles laid on the boundary,but the calculation of boundary forces limits the simulation speed.The virtual particle method generates virtual particles at the boundary,but with the increase of the number of particles,the number of virtual particles required increases too,resulting in a decrease in computational speed,and the separation of fluid and boundary.For solving these problems,this paper proposes a boundary processing method of symmetric area,which meets the real-time requirements on the premise of ensuring fidelity,and with the increase of the number of fluid particles,the increase of the time consumed by this method is obviously slower than that of other traditional methods,which is more suitable for the simulation of complex scenes,while avoiding the separation of fluid and boundary at the boundary.The CSF(continue surface tension)method is a common method for dealing with surface tension.It can calculate the surface tension as volume force,which greatly reduces the effect of surface shape on curvature calculation,whereas in fact curvature calculation is only related to the shape of the surface.To solve this problem,the CSF method is improved and a surface tension calculation method based on surface particle extraction is proposed,which reduces the error of the traditional CSF method in calculating curvature,and improves the calculation speed.The simulation results verify the effectiveness of the proposed method.
作者
朱晓临
张义群
郭清伟
ZHU Xiao-lin;ZHANG Yi-qun;GUO Qing-wei(School of Mathematics,Hefei University of Technology,Hefei Anhui 230009,China)
出处
《图学学报》
CSCD
北大核心
2020年第1期10-17,共8页
Journal of Graphics
基金
国家自然科学基金项目(61432004,61672202)
安徽省自然科学基金项目(1408085MKL16,1508085QF128)
关键词
SPH方法
流体模拟
边界处理
对称区域
表面张力
CSF方法
表面粒子提取
SPH method
fluid simulation
boundary processing
symmetric region
surface tension
CSF method
surface particle extraction
