Visco–Resistive Dissipation in Transient Reconnection Driven by the Orszag–Tang Vortex
Visco–Resistive Dissipation in Transient Reconnection Driven by the Orszag–Tang Vortex
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DOI：
10.1007/s11207-013-0226-7
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发表时间：
2013-01
期刊：
影响因子：
2.8
通讯作者：
C. Armstrong;I. Craig
中科院分区：
文献类型：
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作者：
C. Armstrong;I. Craig
粘性效应预计将大大有助于太阳耀斑中的重联能量释放机制。虽然简单的缩放参数的基础上迎面重联表明，粘性耗散可能占主导地位的电阻耗散，目前还不清楚这些发现是否可以应用在更一般的合并情况。在这里，我们进行并排平面重联模拟驱动的Orszag-Tang涡，经典和Braginskii形式的粘度。这种配方的优点是提供了一个自主的MHD系统，开发强电流层，维持大规模的涡旋剪切流。耗散率被证明遵循基于解析的标度律，这表明从大规模的非均匀速度场产生的粘性损失很可能占主导地位的电流片重连解决方案中的电阻性损失。
Viscous effects are expected to significantly contribute to reconnective energy release mechanisms in solar flares. While simple scaling arguments based on head-on reconnection suggest that viscous dissipation may dominate resistive dissipation, it is not clear whether these findings can be applied in more general merging situations. Here we perform side-by-side planar reconnection simulations driven by the Orszag–Tang vortex, for both classical and Braginskii forms of the viscosity. This formulation has the advantage of providing an autonomous MHD system that develops strong current layers, sustained by large-scale vortical shearing flows. The dissipation rates are shown to follow analytically based scaling laws, which suggest that viscous losses generated from large-scale non-uniform velocity fields are likely to dominate resistive losses in current-sheet reconnection solutions.