非理想MHD流的奇异吸引子与混沌现象

本文提出并研究了在剪切磁场中非理想MHD流的Rayleigh-Bnard问题的一个模型,得到了关于这个模型的一个新的非线性微分方程组。理论和数值分析表明:这组方程蕴含一个奇异吸引子,它具有不同于Lorenz吸引子的一些新特性;更重要的是,已知的三条通往混沌的道路并存于这个模型之中。应当指出,在迄今所有已知的向混沌态过渡的三条道路共存的模型中，我们的方程组是唯一没有外部周期驱动项的，更直接地体现了非线性确定论系统的“内在”随机件、另外，对这个简单模型进行数值模拟．我们观察到磁力线的随机运动、磁力线重联和磁岛 关键词：

STRANGE ATTRACTOR AND CHAOTIC PHENOMENA IN NON-IDEAL MHD FLOW

A model on the Rayleigh-Benard problem of a non-ideal MHD flow in a sheared magnetic field is proposed and studied. A new set of nonlinear differential equations for the model bas been derived. Theoretical and numerical analysis shows that the set of equations implies a strange attractor with several novel features differing from Lorenz attractor and, in particular, the coexistence of all three routes to chaos in that model. Among the well-known models with these routes, so far, our system of equations is the unique one without any extrinsic periodic driving term. It exhibits more immediately the intrinsic stochasticity of deterministic nonlinear system. The stochastic motion and reconnection of magnetic field-lines, and the creation of magnetic islands are observed in numerical simulating of this set of equations.