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arXiv 1612.01482math.NAcs.NA
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多项式鲁棒稳定性分析:用于斯托克斯方程的H(div)-符合有限元

Polynomial robust stability analysis for $H(\textrm{div})$-conforming finite elements for the Stokes equations

TU Wien(维也纳工业大学)

Philip L. Lederer, Joachim Schöberl

AI总结:

本文研究了斯托克斯问题的不连续Galerkin方法,采用H(div)-符合有限元以实现精确质量守恒和压力无关误差估计。通过证明k-鲁棒LBB条件,得出了高阶近似的最优误差估计。

摘要:

本文考虑了斯托克斯问题的不连续Galerkin方法离散化。我们使用H(div)-符合有限元,因其提供精确的质量守恒和压力无关的误差估计。本文的主要方面在于高阶近似的分析。我们证明所考虑的方法对多项式阶k具有均匀稳定性,并提供最优误差估计:‖u - u_h‖_{1_h} + ‖Π^{Q_h}p - p_h‖ ≤ c(h/k)^s‖u‖_{s+1}。为了推导这些估计,我们证明了k-鲁棒LBB条件。这个证明基于一个多项式H²稳定的扩展算子。这个扩展算子本身对C⁰连续的不连续Galerkin方法在四阶问题的数值分析具有兴趣。

英文摘要:

In this work we consider a discontinuous Galerkin method for the discretization of the Stokes problem. We use $H(\textrm{div})$-conforming finite elements as they provide major benefits such as exact mass conservation and pressure-independent error estimates. The main aspect of this work lies in the analysis of high order approximations. We show that the considered method is uniformly stable with respect to the polynomial order $k$ and provides optimal error estimates $ \| \boldsymbol{u} - \boldsymbol{u}_h \|_{1_h} + \| Π^{Q_h}p-p_h \| \le c \left( h/k \right)^s \| \boldsymbol{u} \|_{s+1} $. To derive those estimates, we prove a $k$-robust LBB condition. This proof is based on a polynomial $H^2$-stable extension operator. This extension operator itself is of interest for the numerical analysis of $C^0$-continuous discontinuous Galerkin methods for $4^{th}$ order problems.

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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