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arXiv math/0509331math.NAcs.NAmath.AP
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非结构拟一致网格上的Lax-Wendroff型定理

A Lax-Wendroff type theorem for unstructured quasiuniform grids

Volker Elling

AI总结:

将Lax-Wendroff定理推广到拟一致网格,证明若守恒相容格式的近似解有界几乎处处收敛,则极限是弱解;若满足离散熵不等式,则为熵解。

摘要:

Lax和Wendroff的一个著名定理指出:对于双曲守恒律系统,如果由守恒相容数值格式生成的近似解序列在网格参数趋于零时有界几乎处处收敛,则极限是系统的弱解。此外,如果格式还满足离散熵不等式,则极限是熵解。原始定理适用于均匀笛卡尔网格;本文将其推广到拟一致网格(具有Lipschitz边界单元)、一致连续非齐次数值通量和非线性非齐次源项。这种推广允许讨论新的应用,如局部时间步长、移动顶点网格和守恒重映射。一个反例表明该定理对任意非拟一致网格不成立。

英文摘要:

A well-known theorem of Lax and Wendroff states that if the sequence of approximate solutions to a system of hyperbolic conservation laws generated by a conservative consistent numerical scheme converges boundedly a.e. as the mesh parameter goes to zero, then the limit is a weak solution of the system. Moreover, if the scheme satisfies a discrete entropy inequality as well, the limit is an entropy solution. The original theorem applies to uniform Cartesian grids; this article presents a generalization for quasiuniform grids (with Lipschitz-boundary cells) uniformly continuous inhomogeneous numerical fluxes and nonlinear inhomogeneous sources. The added generality allows a discussion of novel applications like local time stepping, grids with moving vertices and conservative remapping. A counterexample demonstrates that the theorem is not valid for arbitrary non-quasiuniform grids.

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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