EXPERIMENTAL-ANALYSIS OF SELF-SIMILARITY AND RANDOM CASCADE PROCESSES- APPLICATION TO FULLY-DEVELOPED TURBULENCE DATA

In the context of fully developed turbulence, Castaing et al. [10] hav e recently advocated a description of a random cascade process in term s of a kernel G(aa')(x) that characterizes the nature of the cascade w hen going from a scale a' to a finer scale a. We elaborate on a method to estimating, directly from experimental data, the shape of G(aa') f or all scales a and a'. We apply this method to turbulent velocity dat a and we show that it provides very instructive informations about the soundness of various phenomenological models for the intermittency ch aracter of turbulent flows.