An Open Boundary Condition for High-order Solutions of Magnetohydrodynamics on Unstructured Grids
An Open Boundary Condition for High-order Solutions of Magnetohydrodynamics on Unstructured Grids
复制标题
非结构化网格上磁流体动力学高阶解的开放边界条件
DOI：
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发表时间：
2020
期刊：
影响因子：
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通讯作者：
C. Liang
中科院分区：
文献类型：
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作者：
Xiaoliang Zhang;C. Liang
本文提出了一种基于特征线的磁流体动力学（MHD）方程组开边界条件。该算法是精心设计和实施的背景下的高阶通量重建（FR）计划下的广义拉格朗日乘子（GLM）-MHD方程组。它是通过将特征方程的贡献直接加到FR格式中的修正通量项上来实现的，而无需沿沿着边界面求解与时间相关的特征方程。CBC方法被证明是更准确和强大的比常用的零法向导数（ZND）和近似黎曼求解边界条件（ARBC）在解决一维，二维和三维测试问题。CBC方法被成功地应用于模拟具有挑战性的问题，磁重联，其他选项未能得到稳定的结果，在长时间的积分。
In this paper a characteristics-based open boundary condition (CBC) is proposed for the magnetohydrodynamic (MHD) system of equations. The algorithm is carefully designed and implemented in the context of a high-order flux reconstruction (FR) scheme under the Generalised Lagrange Multiplier (GLM)-MHD system of equations. It is implemented by adding the contribution of the characteristic equation directly to the corrected flux term in the FR scheme dispensing with solving time-dependent characteristic equations along boundary faces. The CBC method is shown to be more accurate and robust than commonly used zero normal derivative (ZND) and approximate Riemann solver boundary conditions (ARBC) in solving 1D, 2D, and 3D test problems. The CBC method is successfully applied to simulate challenging problems of magnetic reconnection for which other options failed to get stable results over long-period time integration.