Pressure Boundaries for Implicit Incompressible SPH
Pressure Boundaries for Implicit Incompressible SPH
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DOI：
10.1145/3180486
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发表时间：
2018-07-01
影响因子：
6.2
通讯作者：
Teschner, Matthias
中科院分区：
文献类型：
--
作者：
Band, Stefan;Gissler, Christoph;Teschner, Matthias
隐式不可压缩SPH （IISPH）求解压力泊松方程（PPE）。虽然PPE的解决方案提供流体样品的压力，但嵌入式边界处理不计算边界样品的压力。相反，IISPH使用各种近似来弥补这一缺陷。在本文中，我们将说明这些IISPH近似的问题。我们特别推导了压力边界，这是一种新的边界处理方法，通过计算边界样本上有物理意义的压力值来克服以前的MPH问题。这基本上是通过延长个人防护装备来实现的。我们详细描述了由于将边界样本纳入PPE而带来的额外技术挑战。因此，我们使用以体积为中心的SPH离散，而不是通常使用的以密度为中心的离散。我们进一步分析了所提出的边界处理的性质，并将其与以前的IISPH边界处理进行了比较。除了提出的边界处理在边界样本上提供物理上有意义的压力和压力梯度之外，我们还展示了进一步的好处，例如减少压力振荡，改进求解器收敛性，以及更大的可能时间步长。流体样品的内存占用减少，性能增益系数高达五比IISPH提出。
Implicit incompressible SPH (IISPH) solves a pressure Poisson equation (PPE). While the solution of the PPE provides pressure at fluid samples, the embedded boundary handling does not compute pressure at boundary samples. Instead, IISPH uses various approximations to remedy this deficiency. In this article, we illustrate the issues of these IISPH approximations. We particularly derive Pressure Boundaries, a novel boundary handling that overcomes previous MPH issues by the computation of physically meaningful pressure values at boundary samples. This is basically achieved with an extended PPE. We provide a detailed description of the approach that focuses on additional technical challenges due to the incorporation of boundary samples into the PPE. We therefore use volume-centric SPH discretizations instead of typically used density-centric ones. We further analyze the properties of the proposed boundary handling and compare it to the previous IISPH boundary handling. In addition to the fact that the proposed boundary handling provides physically meaningful pressure and pressure gradients at boundary samples, we show further benefits, such as reduced pressure oscillations, improved solver convergence, and larger possible time steps. The memory footprint of fluid samples is reduced and performance gain factors of up to five compared to IISPH are presented.