Cappello S, Escande DF
Consorzio RFX, Corso Stati Uniti 4, 35127 Padova, Italy and Consiglio Nazionale delle Ricerche, Italy.
Phys Rev Lett. 2000 Oct 30;85(18):3838-41. doi: 10.1103/PhysRevLett.85.3838.
A scaling approach to the simplest viscoresistive MHD model reveals that the Prandtl number acts only through the inertia term. When this term is negligible the dynamics is ruled by the Hartmann number H only. This occurs for the reversed field pinch dynamics as seen by numerical simulation of the model. When H is large the system is in a multiple helicity state. In the vicinity of H = 2500 the system displays temporal intermittency with laminar phases of quasi-single-helicity (SH) type. For lower H's two basins of SH are shown to coexist. SH regimes are of interest because of their nonchaotic magnetic field.
对最简单的粘滞磁流体动力学模型采用标度方法研究发现，普朗特数仅通过惯性项起作用。当该项可忽略不计时，动力学仅由哈特曼数H决定。如该模型的数值模拟所示，反向场箍缩动力学就是这种情况。当H很大时，系统处于多螺旋度状态。在H = 2500附近，系统呈现出准单螺旋度（SH）型层流相的时间间歇性。对于较低的H值，两个SH吸引子共存。SH状态因其非混沌磁场而备受关注。
