SCALE SIMILARITY OF THE VELOCITY STRUCTURE FUNCTIONS IN FULLY-DEVELOPED MAGNETOHYDRODYNAMIC TURBULENCE

Turbulence theory has been recently enriched by the concept of extended self-similarity introduced by Benzi et al. [Phys. Rev. E 48, R29 (1993)] which showed that an extended scaling range, including both the inertial and the dissipative regions, can be observed when the usual qth-order velocity structure functions are plotted against the structure function of the third order. The same concept has been reviewed by Stolovitzky and Sreenivasan [Phys. Rev. E 48, R33 (1993)], whose high resolution measurements show the existence of two scaling regions which become increasingly distinct as the order of the velocity structure function increases. In this paper, by using a shell model for three-dimensional magnetohydrodynamic (MHD) turbulence, we show that the extended self-similarity could be an interesting concept also in fully developed MHD turbulence.