准周期性磁结构的形成过程及其特征的数值分析

THE NUMERICAL ANALYSIS FOR THE FORMATION PROCESSES AND CHARACTERISTICS OFQUASIPERIODIC MAGNETIC STRUCTURES

在入流马赫数ＭＡ为０．１－０．４范围内，选取不同的入流，逐一考察在可压缩导电介质中磁场重联的类型随磁雷诺数Ｒｍ的变化．大量的数值结果表明：在不同入流驱动下，磁雷诺数（Ｒｍ）均有临界值存在，如果等离子体系统逐渐趋于稳定的单Ｘ线重联；若间歇性的次级撕裂产生了重复出现的磁结构，而且Ｍａ越大产生间歇性次级撕裂的临界值越高，与ＭＡ之间基本上符合线性关系．此外还发现，当多重Ｘ线重联间歇性地出现时，有关物理量发生准周期性地振荡．

For different values of the plasma inflow at boundary in 0.1-0.4 range ofAlfvenic Mach number MA, the dependence of reconnection effect as of time on magnetic Reynolods number Rm is investigated by turns in compressible plasma.Based on many numerical results we find that for each inflow there exists a corresponding critical value of magnetic Reynolds number at which point the system will shift from a branch of steady single X line reconnection to a branch of quasiperiodic formation of small magnetic islands generated by secondary tearing.The larger the inflow Mach number MA,the higher the critical value of magnetic Reynolds number And the relation between MA and is nearly linear.In addition, it is found that the quasiperiodic oscillations of some physical variables take place with the intermittent formation of multiple X-line reconnection.