抄録
Statistical properties of magneto-hydrodynamic turbulence are investigated theoretically using the modified zero-fourth cumulant approximation. A set of two dynamical equations for kinetic and magnetic energy spectra is integrated numerically for Prandtl number unity. The equipartition between kinetic and magnetic energy spectra is shown to be attained in high wavenumbers after a short elapse of time, but a significant difference between them is found in low wavenumbers. The energy spectrum of the form k−3⁄2 predicted by Kraichnan is not confirmed from our numerical results. Statistical quantities such as the total energy, the enstrophy and the micro-scale Reynolds number are calculated from the energy spectra. A phenomenological theory is also developed to obtain a decay law of the total energy and it is compared with the results of the numerical calculations.
