Numerical study of energy transport in expanding lightning return stroke channel
In previous work we developed a uni ed lightning return stroke solver to simulate the complicated return stroke phenomena Q.Chen et.al.,Phys.Plasmas,21,032901 (2014).The main part of this numerical solver consists of speci ed pulse current models,plasma equations of state and a two-dimensional Eulerian nite difference code for solving the non-ideal magnetohydrodynamic (MHD) equations including the effects of self-consistent magnetic eld,thermal conduction,resistivity,gravity and radiation transfer.The differential equations are kept in the conservative form and modern high-accuracy shock capturing schemes are equipped,e.g.,the 5- order weighted essentially non-oscillatory (5WENO) scheme combined with Lax-Friedrichs (LF) ux splitting method is introduced for computing the convection terms of the MHD equations,where the arti cial viscosity is used and the 3-order total variation diminishing (TVD) Runge- Kutta integral operator is also equipped.The numerical algorithms for non-ideal terms,e.g.,radiation transfer,resistivity and thermal conduction,are implemented via physical phenomena separating method which is called operator splitting method in mathematics.To describe the radiation transfer,the assumption that the radiation in lightning return stroke channel is in local thermodynamic equilibrium (LTE) with plasma components is introduced and the ux limited diusion algorithm with grey opacities is implemented.The transport coe cients and plasma equations of state of lightning return stroke channel are obtained from detailed particle population distribution calculation,which makes the numerical model is self-consistent.In previous work this numerical solver was systematically validated via theoretical solutions and previous numerical results.In this work the energy transport problems in expanding lightning return stroke channels are intensively studied via the numerical solver,which includ the balance between power injection and release,the evolution characters of different parts in total energy,the dynamical processes in uenced by radiation cooling and energy transfer caused by population distribution evolution.The nuerical results are consistent with the conservation law.The discussions in this work give more intensive knowledge about return stroke process which are of signi cance to lightning physics.
Magnetohydrodynamics Radiation Transfer Self-consistent Modeling Conservation Law Shock Capturing Schemes
Qiang Chen Bin Chen Run Xiong Zhaoyang Cai Boao Xu
National Key Laboratory of Electromagnetic Environment and Electro-optical Engineering,PLA University of Science and Technology, Nanjing 210007, Peoples Republic of China
国际会议
The 8th International Conference of Computational Fluid Dynamics, (ICCFD8)(第八届国际计算流体力学会议)
成都
英文
1-9
2014-07-25（万方平台首次上网日期，不代表论文的发表时间）