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arXiv 2310.03089math.NAcs.NA
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一种用于曲面偏微分方程的自适应稳定化迹有限元方法

An adaptive stabilized trace finite element method for surface PDEs

Timo Heister, Maxim A. Olshanskii, Vladimir Yushutin

AI总结:

本研究提出了一种求解水平集曲面低正则性椭圆问题的自适应稳定化TraceFEM,设计了实用误差指示子,证明了其可靠性,数值实验验证了方法的最优收敛性与鲁棒性。

摘要:

本文提出了稳定化迹有限元方法(TraceFEM)的自适应版本,该方法旨在利用嵌入空间中形状规则的体网格,求解水平集曲面上的低正则性椭圆问题。针对基于$Q_1$和$Q_2$多项式族的一次与二次连续迹空间,本文研究了两种稳定化变体:梯度跳变面稳定化与法向梯度体积稳定化。我们提出了一种实用的误差指示子,它通过估计有限元解的导数在背景网格面上的“跳变”来计算误差,避免了在离散曲面单元的隐式定义曲线边上进行任何量的积分。对于体单元上的分段三线性多项式$Q_1$族,求解-估计-标记-细化策略结合所提出的误差指示子,可达到二维问题典型的最优收敛速率。我们还提供了后验误差估计,证明了该误差指示子对于$Q_1$和$Q_2$单元以及两种稳定化类型均具有可靠性。在数值实验中,我们评估了该误差指示子的可靠性与效率。结果显示,两种稳定化方法的性能相当,而最低次有限元空间似乎是自适应TraceFEM框架下更鲁棒的选择。

英文摘要:

The paper introduces an adaptive version of the stabilized Trace Finite Element Method (TraceFEM) designed to solve low-regularity elliptic problems on level-set surfaces using a shape-regular bulk mesh in the embedding space. Two stabilization variants, gradient-jump face and normal-gradient volume, are considered for continuous trace spaces of the first and second degrees, based on the polynomial families $Q_1$ and $Q_2$. We propose a practical error indicator that estimates the `jumps' of finite element solution derivatives across background mesh faces and it avoids integration of any quantities along implicitly defined curvilinear edges of the discrete surface elements. For the $Q_1$ family of piecewise trilinear polynomials on bulk cells, the solve-estimate-mark-refine strategy, combined with the suggested error indicator, achieves optimal convergence rates typical of two-dimensional problems. We also provide a posteriori error estimates, establishing the reliability of the error indicator for the $Q_1$ and $Q_2$ elements and for two types of stabilization. In numerical experiments, we assess the reliability and efficiency of the error indicator. While both stabilizations are found to deliver comparable performance,the lowest degree finite element space appears to be the more robust choice for the adaptive TraceFEM framework.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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