Abstract
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.
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Acknowledgements
The authors would like to thank Yuri E. Litvinenko for his assistance with the article. Conversations with E. Kalnins have also been much appreciated.
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Armstrong, C.K., Craig, I.J.D. Visco–Resistive Dissipation in Transient Reconnection Driven by the Orszag–Tang Vortex. Sol Phys 283, 463–471 (2013). https://doi.org/10.1007/s11207-013-0226-7
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DOI: https://doi.org/10.1007/s11207-013-0226-7