天文学进展2016，Vol.34Issue(4)：459-476,18.DOI:10.3969/j.issn.1000-8349.2016.04.08
粒子云网格方法在大尺度湍流磁重联研究中的应用和进展
Applications and Development in Particle-in-Cell Methods for Investigating Large-Scale Turbulent Magnetic Reconnection
摘要
Abstract
The particle-in-cell (PIC) method, employed since the 1940s, has become one of the preferred tools since 1980s in Magnetohydrodynamics numerical simulation field. In this work, the history, fundamentals, recent advances and future challenges of PIC are introduced from the statistical mechanics and solar fractal turbulent magnetic reconnection aspect. The fractal turbulent current sheet (FTCS) structure as a source for both small-scale reconnec-tions, leading to nano-flares and to larges-scales one, leading to long-duration flares or giant arcades. It becomes now very attractive in solar flare and flare-like (e.g. CME) phenomena research as it can address many open issues in coronal heating and particle acceleration field. The large scale single FTCS involving multiple current sheets inevitably inherit the same size-and time-step problems, allowing us to simulate macro turbulent and particle acceleration in only a very small region. PIC, a full kinetic approach, is suitable to exploring the turbulent dynamic mechanism and multiple turbulent fractal properties. But the narrowness of the simulation region still imposes strong limitations on the number of particles being accelerated in PIC simulations. <br> In the paper, the improved PIC algorithm is given through combined Yee Grid and Lattice Grid in Boris pusher and finite-difference time-domain (FDTD) framework, and rel-atively hybrid PIC and Lattice Boltzmann (HPIC-LBM) numerical simulation approach is established. In HPIC-LBM, the super-particle is re-defined to permit simulating high particle density of β plasmoid (photosphere, chromosphere and corona), the simulation regime up to size compatible with observations; The distribution function is re-defined to extend the computating region well beyond the null point, to explore the effect on the acceleration of different magnitudes of the transverse magnetic filed, to investigate self-consistently include the electric and magnetic fields induced by the acceleration particles, to analyze the electric and magnetic filed induced by the particles acceleration as well as background field in the whole computation region. All these new features of HPIC-LBM will make the PIC based virtual test of large scale FTMR can be done on Tianhe series supercomputer platform.关键词
等离子体动力学属性/粒子云网格方法/玻尔兹曼方法/大尺度湍流磁重联/太阳耀斑及日冕物质抛射Key words
kinetic theory/particle in cell method/lattice Boltzmann method/large scale fractal turbulent magnetic reconnection/solar flare and CME分类
天文与地球科学引用本文复制引用
朱伯靖,林隽..粒子云网格方法在大尺度湍流磁重联研究中的应用和进展[J].天文学进展,2016,34(4):459-476,18.基金项目
国家自然科学基金(11273055,11333007, U1631130)；中国科学院前沿科学重点研究计划项目(QYZDJ-SSW-SLH012)；中国科学院“宇宙结构起源”B 类先导专项(XDB09040202)；973项目(2013CB01503)；南京大学现代天文与天体物理教育部重点实验室开放基金；国家自然科学基金-广东联合基金超级计算科学应用研究专项资助(2015461,2015462) （11273055,11333007, U1631130）
