Probability distribution functions in turbulent flows and shell models

Abstract

In the multifractal framework some recent results [Phys. Rev. Lett. 67, 2295 (1991)] on the probability distribution functions (pdf) in fully developed turbulence are reviewed, for the increments of the velocity field in the inertial range and for transversal gradients. New comparisons are also produced, in the same scenario, with clusters of isogradients and with pdf evaluated from a numerical simulation of a shell model. The Reynolds dependence of the flatness in the multifractal model is discussed. © 1993 American Institute of Physics.