粘滞效应对非线性电阻撕裂模的影响

本文研究粘滞效应对非线性电阻撕裂模的影响。利用准环坐标将具有标量电阻率和粘滞系数的MHD方程简化为一组无量纲的非线性方程。并对这组方程采用二步交替隐式差分格式进行数值计算。结果给出了2/1模的演变过程对无量纲粘滞系数的依赖关系和电流密度的分布。发现粘滞效应对饱和磁岛宽度的修正大约为5％(此时R=10~(-5)),同时发现由于粘滞效应的引入导致电流分布在奇异面附近的涨落明显减小。

EFFECT OF VISCOSITR ON NONLINEAR RESISTIVE TEARING MODE

The effect of viscosity on the nonlinear resistive tearing mode is studied in the paper. We reduce MHD equations with scalar resistivity and viscosity to a set of dimensionless nonlinear equations in a framework of quasi-toroidal coordinates. Then, the set of equations is calculated with a two-step implicit difference scheme. The evolution of 2/1 mode relative to the dimensionless viscous coefficient and the distribution of current density is given. We find that the modification of viscous effect on saturated island width is about 5% (R=10-5), meanwhile the viscosity causes considerable reduction of the current density fluctuations near singular surfaces.