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arXiv 1607.07409math.NAcs.NA
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保守的多维半拉格朗日有限差分方案:稳定性及其在动能学和流体模拟中的应用

Conservative Multi-Dimensional Semi-Lagrangian Finite Difference Scheme: Stability and Applications to the Kinetic and Fluid Simulations

Xiamen University(厦门大学);University of Catania(卡塔尼亚大学);University of Houston(休斯顿大学)

Tao Xiong, Giovanni Russo, Jing-Mei Qiu

AI总结:

本文提出一种无维度分裂的多维保守半拉格朗日有限差分方案,通过引入通量差形式的保守修正程序,确保局部质量守恒并引入时间步长约束,用于动能学和流体模拟。

摘要:

本文提出了一种无维度分裂的多维保守半拉格朗日有限差分方案。该半拉格朗日方案基于从网格点向后追踪特征线,但不保证总质量守恒。为确保质量守恒,我们提出了一种基于通量差形式的保守修正程序,该程序保证局部质量守恒,同时引入时间步长约束以保证稳定性。我们从微分方程的角度理论研究了这些稳定性约束,并通过傅里叶分析线性PDEs。该方案通过经典二维线性被动传输问题(如线性对流、旋转和涡旋变形)进行测试,并应用于求解非线性Vlasov-Poisson系统,使用[Qiu和Russo, 2016]提出的高阶追踪机制。该高阶特征追踪方案被推广到非线性引导中心Vlasov模型和不可压缩欧拉系统。通过广泛的数值测试,证明了所提出保守半拉格朗日方案的有效性。

英文摘要:

In this paper, we propose a mass conservative semi-Lagrangian finite difference scheme for multi-dimensional problems without dimensional splitting. The semi-Lagrangian scheme, based on tracing characteristics backward in time from grid points, does not necessarily conserve the total mass. To ensure mass conservation, we propose a conservative correction procedure based on a flux difference form. Such procedure guarantees local mass conservation, while introducing time step constraints for stability. We theoretically investigate such stability constraints from an ODE point of view by assuming exact evaluation of spatial differential operators and from the Fourier analysis for linear PDEs. The scheme is tested by classical two dimensional linear passive-transport problems, such as linear advection, rotation and swirling deformation. The scheme is applied to solve the nonlinear Vlasov-Poisson system using a a high order tracing mechanism proposed in [Qiu and Russo, 2016]. Such high order characteristics tracing scheme is generalized to the nonlinear guiding center Vlasov model and incompressible Euler system. The effectiveness of the proposed conservative semi-Lagrangian scheme is demonstrated numerically by our extensive numerical tests.

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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