Mean-field approximation and extended self-similarity in turbulence - art.no. 234501

Recent experimental discovery of extended self-similarity (ESS) was one of the most interesting developments. enabling precise determination of the sc aling exponents of fully developed turbulence. A sufficient condition for e xtended self-similarity in a general dynamical system is derived in this pa per. It is also shown that if the pressure-gradient contributions are expre ssed in terms of velocity differences in the mean-field approximation [V. Y akhot, Phys. Rev. E 63, 026307 (2001)], then the ESS is a consequence of th e Navier-Stokes equations.