SPH流固耦合模拟自适应采样固壁虚粒子边界处理方法

Adaptive Sampling Method for Solid Wall Virtual Particle Boundary Handling in SPH Fluid Solid Coupling Simulation

固壁虚粒子边界处理方法是流体模拟中一种主要边界处理方法,但其不能确保流体粒子不穿透固体边界,并且计算量较大。为防止流体粒子穿透边界,在边界附近设置一个阻尼区,阻尼区内的流体粒子被边界施加一个弹性力和一个和流体粒子运动速度方向相反的阻尼力,使得边界附近流体粒子更加稳定。为减少计算量,提出两种边界粒子自适应采样法:一种是依据边界周围粒子数目的不同,边界粒子自适应地采样质量不同的大小粒子;另一种是依据边界周围粒子数目的不同,边界粒子自适应的采样不同层数的相同质量粒子。与传统的固体边界粒子采样方法相比,该方法减少了边界粒子数目,加快了模拟速度,节省了计算机内存,基于GPU加速技术实现的三维流体模拟,能够进行实时交互。

The method for solid wall virtual particle boundary handling is a main boundary handling method in fluid simulation,while it cannot ensure that no fluid penetrates the solid boundary,and requires a huge amount of computation.To prevent fluid particles from penetrating the boundary,in this paper a damp zone is set up near the boundary,and each fluid particle in this zone will be applied by the boundary with an elastic force and a damping force that is opposite to the moving velocity of the fluid particle.Therefore,the particles near the boundary become more stabilized.To reduce the amount of computation,this paper proposes two adaptive sampling methods for boundary particles based on different numbers of particles around the boundary:one is to adaptively sample particles of different masses;the other is to adaptively sample particles of the same mass in different layers.Compared with the traditional method for solid boundary particle sampling,these two adaptive sampling methods reduce the number of boundary particles,accelerate the simulation speed and save the computer memory.In addition,all of the 3D fluid simulations in this paper are based on the GPU acceleration technique,and can interact in real time.