Nonlinear mode coupling and energetics of driven magnetized shear-flow turbulence

To comprehensively understand the saturation of two-dimensional (2D) magnetized Kelvin–Helmholtz-instability-driven turbulence, energy transfer analysis is extended from traditional interaction between scales to include eigenmode interactions, by using nonlinear couplings linear eigenmodes ideal instability. While both kinetic and magnetic energies cascade small scales, a significant fraction turbulent deposited unstable modes in fluctuation spectrum shown be re-routed conjugate-stable at instability scale. They remove forward its inception. The remaining cascading flux attenuate exponentially scale, dictated large-scale stable modes. Guided widely used instability-saturation assumption, general quasi-linear model tested retaining all interactions except those that couple These complex are analytically removed magnetohydrodynamic equations novel technique. Observations an explosive vortex separation instead well-known merger 2D, dramatic enhancement turbulence level spectral fluxes, reduced small-scale dissipation length show critical role saturation. Possible reduced-order models proposed for fusion astrophysical plasmas, based on eigenmode-expanded analyses.