Comparing turbulent cascades and heating vs spectral anisotropy in solar wind via direct simulations

摘要: In a previous work (MGV18), we showed numerically that the turbulent cascade generated by quasi-2D structures (with wave vectors mostly-perpendicular to mean magnetic field) is able generate temperature profile close one observed in solar wind ($\simeq 1/R$) range 0.2 $\le R \le$ 1 au. Theory, observations and numerical simulations point another robust structure, radial-slab, with dominant along radial: study here efficiency of radial-slab building $1/R$ profile. As MGV18, solve three-dimensional MHD equations including expansion simulate evolution. We find an isotropic distribution large cross helicity at au, rate, lead again decay rate but anisotropy Surprisingly, concentrates plane transverse radial direction, displaying 1D spectra scalings $k^{-5/3}$ this plane. This supports both idea heating wind, existence two different cascades, slab, origin heating. We conclude sampling spectrum may give poor information on real regime when slab non-negligible part turbulence.