强激光与粒子束, 2018, 30 (1): 012001, 网络出版: 2018-01-30
二维各向异性磁等离子体的无条件稳定ADE-CNAD-FDTD算法
Unconditionally stable auxiliary differential equation Crank-Nicolson-approximate-decoupling FDTD algorithm for 2-D anisotropic magnetized plasma
辅助微分方程 Crank-Nicolson approximate-decoupling算法 时域有限差分 磁等离子体 auxiliary differential equation (ADE) Crank-Nicolson-approximate-decoupling (CNAD) finite-difference time-domain (FDTD) magnetized plasma
摘要
针对二维各向异性磁等离子体提出一种有效的无条件稳定算法,新算法结合了辅助微分方程 (ADE)方法与Crank-Nicolson approximate-decoupling (CNAD)时域有限差分算法仿真各向异性磁等离子体介质。传统的ADE-FDTD方法应用在一维各向异性色散介质具有较高的精度和效率,将提出的新算法ADE-CNAD-FDTD应用到二维各向异性磁等离子体介质中不仅解决了电磁波在具有各向异性和频率色散特性介质中传播的仿真难题,而且去除了CFL稳定性条件。该算法在保留了原有的精度情况下大幅度地提高了计算效率并成为无条件稳定的形式。给出一个算例证明该算法的有效性,通过模拟电磁波在磁等离子体中的传播,仿真结果与传统的ADE-FDTD算法对比,证实了该算法的高效率、无条件稳定性和高精度。
Abstract
An effective unconditionally stable implementation of the auxiliary differential equation Crank-Nicolson-approximate-decoupling finite-difference time-domain (ADE-CNAD-FDTD) algorithm for 2-D anisotropic magnetized plasma is proposed. The conventional ADE-FDTD method for 1-D anisotropic dispersive media has high efficiency and accuracy. This paper extends this method to 2-D anisotropic magnetized plasma with the CNAD scheme. The proposed formulations not only solves the problem that incorporates both anisotropy and frequency dispersion at the same time, but also eliminates the Courant-Friedrich-Levy (CFL) stability constraint. A numerical example has been carried out to validate the proposed formulations in the 2-D FDTD domain composed of anisotropic magnetized plasma. The results prove that the proposed formulations significantly save time and perform stably with acceptable accuracy.
李建雄, 庄永佳, 李现国. 二维各向异性磁等离子体的无条件稳定ADE-CNAD-FDTD算法[J]. 强激光与粒子束, 2018, 30(1): 012001. Li Jianxiong, Zhuang Yongjia, Li Xianguo. Unconditionally stable auxiliary differential equation Crank-Nicolson-approximate-decoupling FDTD algorithm for 2-D anisotropic magnetized plasma[J]. High Power Laser and Particle Beams, 2018, 30(1): 012001.