NUMERICAL AND ANALYTICAL ESTIMATES FOR THE STRUCTURE FUNCTIONS IN 2-DIMENSIONAL MAGNETOHYDRODYNAMIC FLOWS

In two-dimensional magnetohydrodynamic turbulence, the Kraichnan-Iroshnikov dimensional analysis suggests a linear scaling law for the exponents ζp=p/4 of the structure functions for the Elsässer variables z± = u±B. Numerical simulations are presented and higher order structure functions are calculated using the extended self-similarity hypothesis of Benzi et al. [Phys. Rev. E 48, R29 (1993)]. In addition, an estimate for the first structure function ζ1≥=1/ 4 is derived using a geometric technique introduced by Constantin and Procaccia [Phys. Rev. E 47, 3307 (1993)] in the the context of the transport of a passive scalar in three-dimensional Navier-Stokes turbulence. © 1995 American Institute of Physics.