Cascade models for magnetohydrodynamic turbulence
This paper presents studies of cascade models for magnetohydrodynamic turbulence. Most of the computations are performed using the complex version of the model introduced by Gloaguen. An alternative model, which conserves the equivalent of the magnetic helicity, is also derived. In the first part of the paper the Alfvén effect is neglected and the stationary solutions, most of which are unstable, are discussed. For purely kinetic turbulence [P(n) = Q(n)] the phenomenon of coherent structures in K(n) space is presented. In the second part of the paper the Alfvén effect is included. For the simplest case of a constant large-scale field B(0), energy spectra are flatter than expected. The paper discusses the refinements of the models by assuming B(0) to be the actual fluctuating field and by introducing intermittency into the spectra. This produces values nearer to the Iroshnikov-Kraichnan law K(n)(-3/2).
Bibliographic Reference: Article: Physical Review E, Vol. 50 (1994) No. 4, pp. 2702-2711
Record Number: 199510055 / Last updated on: 1995-01-10
Original language: en
Available languages: en