Analysis of fast turbulent reconnection with self-consistent determination of turbulence timescale

Abstract

We present results of a Reynolds-averaged turbulence model simulation on the problem of magnetic reconnection. In the model, in addition to the mean density, momentum, magnetic field, and energy equations, the evolution equations of the turbulent cross-helicity W, turbulent energy K, and its dissipation rate ε are simultaneously solved to calculate the rate of magnetic reconnection for a Harris-type current sheet. In contrast to previous studies based on algebraic modeling, the turbulence time scale is self-determined by the nonlinear evolutions of K and ε, their ratio being a time scale. We compare the reconnection rate produced by our mean-field model to the resistive nonturbulent MHD rate. To test whether different regimes of reconnection are produced, we vary the initial strength of turbulent energy and study the effect on the amount of magnetic flux reconnected in time. We obtain that the time scale of turbulence self-adjusts to always produce fast reconnection.