论文标题
在均匀和多层HP改良的网格上的有限单元格方法的分层多grid方法
Hierarchical multigrid approaches for the finite cell method on uniform and multi-level hp-refined grids
论文作者
论文摘要
这项贡献为在均匀网格和多级HP-差异上解决大规模有限细胞问题的解决方案提供了一种层次多机方法。所提出的方案利用有限单元格方法中使用的基本函数的层次结构性质和多级HP方法,这归因于使用高阶集成的Legendre基础函数和覆盖网格,以产生一种简单且优雅的多族方案。这种简单性反映在以下事实中:所有限制和延长操作员都将不需要明确构造的二进制矩阵减少。粗空间是在不同的多项式顺序和浸入离散化的精炼水平上构建的。元素和斑块添加性施瓦茨平滑技术用于减轻切割单元的影响,导致收敛速率独立于切割构型,网格尺寸,甚至在某些情况下甚至多项式顺序。多机方法应用于由泊松方程和线性弹性引起的二阶问题。一系列数值示例证明了该方案在求解大型沉浸式系统上具有数百万甚至数十亿个未知数在大规模并行机器上的适用性。
This contribution presents a hierarchical multigrid approach for the solution of large-scale finite cell problems on both uniform grids and multi-level hp-discretizations. The proposed scheme leverages the hierarchical nature of the basis functions utilized in the finite cell method and the multi-level hp-method, which is attributed to the use of high-order integrated Legendre basis functions and overlay meshes, to yield a simple and elegant multigrid scheme. This simplicity is reflected in the fact that all restriction and prolongation operators reduce to binary matrices that do not need to be explicitly constructed. The coarse spaces are constructed over the different polynomial orders and refinement levels of the immersed discretization. Elementwise and patchwise additive Schwarz smoothing techniques are used to mitigate the influence of the cut cells leading to convergence rates that are independent of the cut configuration, mesh size and in certain scenarios even the polynomial order. The multigrid approach is applied to second-order problems arising from the Poisson equation and linear elasticity. A series of numerical examples demonstrate the applicability of the scheme for solving large immersed systems with multiple millions and even billions of unknowns on massively parallel machines.