一种改进的光滑粒子流体动力学前处理方法

为了便于对任意边界形状的计算域快速地布置均匀粒子,提出了一种改进的光滑粒子流体动力学前处理方法.该方法是在2012年Colagrossi等提出的算法基础上进行改进后得到的.Colagrossi等提出的算法能够计算一些简单外形分布比较均匀的粒子.然而当光滑长度与初始粒子间距的比值较大时该方法在计算过程中会出现较强的数值震荡问题,收敛速度慢;而且在计算过程中可能会遭遇流体粒子穿透固体壁面的问题.本文通过引入未知因素修正的平滑粒子动力学模型来提高计算稳定性,并通过对边界附近的流体粒子施加边界力来避免流体粒子穿透固体壁面.算例验证结果表明,利用改进后的光滑粒子流体动力学前处理方法能够快速地对各种边界形状的计算域分布均匀粒子,并且避免了流体粒子穿透固体壁面的问题.

An improved pre-processing method for somooth particle hydrodynamics

An improved pre-processing method for smooth particle hydrodynamics is proposed, which can rapidly distribute the uniform particles for the fluid field with an arbitrary boundary. The improved pre-processing method is obtained by improving the algorithm proposed by Colagrossi et al., whose method can distribute the uniform particles in a simple shape. However, when the ratio of the smoothing length to the initial particle space is bigger than unity, the algorithm proposed by Colagrossi et al. has a numerical oscillation and a slow convergence rate; and the fluid particles may penetrate the solid boundary. For solving the problems, the XSPH model is added to improve the algorithm stability, and the boundary force is exerted on the fluid particles near the solid boundary to prevent fluid particles from penetrating wall surface. Verified by showing some exmples, the improved pre-processing method can rapidly distribute the more uniform particles for the fluid field with an arbitrary boundary and prevent fluid particles from penetrating wall surface.
Keywords： smooth particle hydrodynamics pre-processing XSPH boundary force