论文标题
磁岛合并中重新连接参数的缩放：平面剪切流的作用
Scaling of reconnection parameters in magnetic island coalescence: Role of in-plane shear flow
论文作者
论文摘要
2D不可压缩的粘性MHD模型[Mahapatra等。 al。，物理。等离子体28，072103（2021）]用于研究在两个有趣的情况下，在磁岛结合问题中重新连接参数的缩放。首先，研究了在固定系统大小上改变岛屿半宽的效果。随着岛的半宽度的增加，总磁通量含量增加，从而导致上游磁场，上游速度场和非均衡重新连接速率的增加，同时保持归一化速率，下游磁场和电流长度独立于其。有趣的是，发现重新连接速率与上游速度和当前纸的纵横比不同，而不是甜蜜模型的发现。其次，研究了平面剪切流动效应，以保持岛宽度和系统尺寸固定。在这里，计算了当前纸的厚度和长度，上游磁场和速度场成分，重新连接速率和时间，剪切流量长度尺度和振幅的当前板倾斜角。有趣的是，发现当前纸和扩散区域的倾斜角不同。这些差异更强烈。这些结果与带有剪切流的Harris板设置显着不同。结果在地球磁层观测和融合等离子体实验中具有潜在的应用。
A 2D incompressible viscoresistive-MHD model [Mahapatra et. al., Phys. Plasmas 28, 072103 (2021)] is used to study the scaling of reconnection parameters in magnetic island coalescence problem under two interesting scenarios. Firstly, the effect of changing island half-width at a fixed system size is investigated. As the island half-width increases, the total magnetic flux content increases resulting in an increase in upstream magnetic field, upstream velocity field and unnormalized reconnection rate while keeping the normalized rate, downstream magnetic field and current sheet length independent of it. Interestingly, the reconnection rate is found to be different from the upstream and downstream velocity as well as inverse aspect ratio of the current sheet, as opposed to the findings of the Sweet-Parker model. Secondly, the in-plane shear flow effects are studied, keeping the island width and system size fixed. Here thickness and length of the current sheet, the upstream magnetic and velocity field components, reconnection rate and time, current sheet inclination angle with shear flow length scale and amplitude are calculated. Interestingly, the inclination angle of the current sheet and the diffusion region are found to be different. These differences are more in stronger shear flows. These results are significantly different from the Harris sheet setup with shear flow. The results have potential application in the Earth magnetospheric observations and fusion plasma experiments.
