Fluid simulations of three-dimensional reconnection that capture the lower-hybrid drift instability

Abstract

Fluid models that approximate kinetic effects have received attention recently in the modelling of large-scale plasmas such as planetary magnetospheres. In three-dimensional reconnection, both reconnection itself and current sheet instabilities need to be represented appropriately. We show that a heat flux closure based on pressure gradients enables a 10-moment fluid model to capture key properties of the lower-hybrid drift instability (LHDI) within a reconnection simulation. Characteristics of the instability are examined with kinetic and fluid continuum models, and its role in the three-dimensional reconnection simulation is analysed. The saturation level of the electromagnetic LHDI is higher than expected, which leads to strong kinking of the current sheet. Therefore, the magnitude of the initial perturbation has significant impact on the resulting turbulence.

An Energy Conserving Vlasov Solver That Tolerates Coarse Velocity Space Resolutions: Simulation of MMS Reconnection Events

“…(2018) and Allmann‐Rahn et al. (2021). The closure is based on the one‐dimensional Landau fluid closure in Hammett and Perkins (1990) (also Hammett et al., 1992) and takes inspiration from Wang et al.…”

A Parallel Low-Rank Solver for the Six-Dimensional Vlasov-Maxwell Equations

“…For an otherwise fair comparison, we utilize in the full-grid simulations the advantages that an explicitly available grid brings: The positivity preserving limiters are turned on and the velocity splitting is realized via the backsubstitution method [32]. The full grid simulations are performed with the muphy2 multiphysics plasma simulation code [2,33].…”