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arXiv 2401.03089math.NAcs.NAphysics.comp-ph
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双曲守恒律的连续保界间断Galerkin方法

Continuously bounds-preserving discontinuous Galerkin methods for hyperbolic conservation laws

Tarik Dzanic

AI总结:

针对传统间断Galerkin方法限制器仅在离散节点保界、无法满足任意位置解计算鲁棒性的问题,提出一种新型限制方法,通过修正约束泛函仅需单元级标量最小化,实现任意基、阶数和网格下的连续保界,在多类双曲守恒律问题中验证了有效性。

摘要:

对于输运现象的有限元近似,通常需要施加某种形式的限制器,以确保离散解保持良好性态并满足物理约束。然而,这些限制过程通常在离散节点位置执行,当必须在任意位置计算解时(例如,用于自适应网格细化、任意拉格朗日-欧拉求解器中的重映射、重叠网格等),这不足以保证格式的鲁棒性。本文提出了一种用于间断Galerkin方法的新型限制方法,该方法可确保对于任意基函数、近似阶数和网格单元类型,解都是连续保界的(即在整个解多项式上保界)。通过对约束泛函进行修正构造,所提方法仅需对每个单元求解单个空间标量最小化问题,本文还为此提出了一种高效的数值优化流程。在数值实验中,通过在双曲守恒律的高阶非结构间断Galerkin离散中施加连续约束,验证了该方法的有效性,实验涵盖了从满足最大值原理约束的标量输运到满足正性约束的可压缩气体动力学等场景。

英文摘要:

For finite element approximations of transport phenomena, it is often necessary to apply a form of limiting to ensure that the discrete solution remains well-behaved and satisfies physical constraints. However, these limiting procedures are typically performed at discrete nodal locations, which is not sufficient to ensure the robustness of the scheme when the solution must be evaluated at arbitrary locations (e.g., for adaptive mesh refinement, remapping in arbitrary Lagrangian--Eulerian solvers, overset meshes, etc.). In this work, a novel limiting approach for discontinuous Galerkin methods is presented which ensures that the solution is continuously bounds-preserving (i.e., across the entire solution polynomial) for any arbitrary choice of basis, approximation order, and mesh element type. Through a modified formulation for the constraint functionals, the proposed approach requires only the solution of a single spatial scalar minimization problem per element for which a highly efficient numerical optimization procedure is presented. The efficacy of this approach is shown in numerical experiments by enforcing continuous constraints in high-order unstructured discontinuous Galerkin discretizations of hyperbolic conservation laws, ranging from scalar transport with maximum principle preserving constraints to compressible gas dynamics with positivity-preserving constraints.

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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