论文标题

Vlasov-Maxwell方程的渐近保护和持势粒子方法

An Asymptotic-Preserving and Energy-Conserving Particle-In-Cell Method for Vlasov-Maxwell Equations

论文作者

Ji, Lijie, Yang, Zhiguo, Li, Zhuoning, Wu, Dong, Jin, Shi, Xu, Zhenli

论文摘要

在本文中,我们为Vlasov-Maxwell系统开发了一种渐近保护和能量持续的(APEC)粒子(PIC)算法。该算法不仅可以保证离散方案的渐近限制是连续模型的准中性极限的一致且稳定的离散化,而且还可以同时保留高斯的法律和能源保护,因此,在Quasi-Inutral Senutral Intral Intral Intral Condime中,也可以提供稳定的复杂等化系统的稳定模拟。实现这些特性的关键成分包括可以实现渐近保护离散化的广义欧姆法律,并且可以适当地分解电磁场的影响,从而可以适当地使用Lagrange乘法方法来校正动力学能量。我们通过一个维度进行了三个基准测试,研究了APEC方法的性能,包括线性Landau阻尼,颠簸的尾巴问题和两流不稳定性。详细的比较是通过包括经典的显式跨越和先前开发的渐近保护PIC方案的结果进行的。我们的数值实验表明,所提出的APEC方案可以给出精确稳定的模拟动力和准中性方案,以证明该方法交叉尺度的有吸引力。

In this paper, we develop an asymptotic-preserving and energy-conserving (APEC) Particle-In-Cell (PIC) algorithm for the Vlasov-Maxwell system. This algorithm not only guarantees that the asymptotic limiting of the discrete scheme is a consistent and stable discretization of the quasi-neutral limit of the continuous model, but also preserves Gauss's law and energy conservation at the same time, thus it is promising to provide stable simulations of complex plasma systems even in the quasi-neutral regime. The key ingredients for achieving these properties include the generalized Ohm's law for electric field such that the asymptotic-preserving discretization can be achieved, and a proper decomposition of the effects of the electromagnetic fields such that a Lagrange multiplier method can be appropriately employed for correcting the kinetic energy. We investigate the performance of the APEC method with three benchmark tests in one dimension, including the linear Landau damping, the bump-on-tail problem and the two-stream instability. Detailed comparisons are conducted by including the results from the classical explicit leapfrog and the previously developed asymptotic-preserving PIC schemes. Our numerical experiments show that the proposed APEC scheme can give accurate and stable simulations both kinetic and quasi-neutral regimes, demonstrating the attractive properties of the method crossing scales.

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