Local uniform stencil (LUST) boundary condition for arbitrary 3-D boundaries in parallel smoothed particle hydrodynamics (SPH) models
Local uniform stencil (LUST) boundary condition for arbitrary 3-D boundaries in parallel smoothed particle hydrodynamics (SPH) models
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DOI：
10.1016/j.compfluid.2019.06.009
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发表时间：
2019-08
影响因子：
2.8
通讯作者：
G. Fourtakas;J. Dominguez;R. Vacondio;B. Rogers
中科院分区：
文献类型：
--
作者：
G. Fourtakas;J. Dominguez;R. Vacondio;B. Rogers
本文提出了一种新的边界处理的自由表面流体动力学的光滑粒子流体动力学（SPH）方法与图形处理单元（GPU）加速的发展。新的固体边界公式使用虚拟粒子的局部均匀模板（LUST），这些虚拟粒子围绕每个流体粒子并与每个流体粒子一起移动，并且仅当它们位于边界内时才被激活。这解决了目前影响SPH中边界条件的问题，即准确性，鲁棒性和适用性，同时易于并行化，例如在GPU上。在3D中，该方法使用三角形来表示几何形状，并使用光线跟踪程序来识别LUST粒子何时被激活。提出了一种新的修正流行的密度扩散项的处理，以纠正在边界处的压力误差。该方法适用于复杂的任意几何形状，而不需要特殊处理的角落和曲率。本文介绍了从2-D和3-D Poiffille流的结果显示收敛速度典型的弱可压缩SPH。具有金字塔的复杂3-D几何形状中的静水证明了该技术的鲁棒性，其压力分布具有良好的一致性。最后将该方法应用于SPHERIC基准的干床溃坝冲击障碍物，表现出令人满意的协议和收敛的暴力流。
This paper presents the development of a new boundary treatment for free-surface hydrodynamics using the smoothed particle hydrodynamics (SPH) method accelerated with a graphics processing unit (GPU). The new solid boundary formulation uses a local uniform stencil (LUST) of fictitious particles that surround and move with each fluid particle and are only activated when they are located inside a boundary. This addresses the issues currently affecting boundary conditions in SPH, namely the accuracy, robustness and applicability while being amenable to easy parallelization such as on a GPU. In 3-D, the methodology uses triangles to represent the geometry with a ray tracing procedure to identify when the LUST particles are activated. A new correction is proposed to the popular density diffusion term treatment to correct for pressure errors at the boundary. The methodology is applicable to complex arbitrary geometries without the need of special treatments for corners and curvature is presented. The paper presents the results from 2-D and 3-D Poiseuille flows showing convergence rates typical for weakly compressible SPH. Still water in a complex 3-D geometry with a pyramid demonstrates the robustness of the technique with excellent agreement for the pressure distributions. The method is finally applied to the SPHERIC benchmark of a dry-bed dam-break impacting an obstacle showing satisfactory agreement and convergence for a violent flow.