Modeling compressed turbulent plasma with rapid viscosity variations

Abstract

We propose two-equation models in order to capture the dynamics of a turbulent plasma undergoing compression and experiencing large viscosity variations. The models account for possible relaminarization phases and rapid viscosity changes through closures dependent on the turbulent Reynolds and on the viscosity Froude numbers. These closures are determined from a data-driven approach using eddy-damped quasi-normal Markovian simulations. The best model is able to mimic the various self-similar regimes identified in Viciconte et al. [Phys. Rev. E 97, 023201 (1998)] and to recover the rapid transition limits identified by G. N. Coleman and N. N. Mansour [Phys. Fluids A 3, 2255 (1991)].