Fourth-order moments of longitudinal- and transverse-velocity structure functions
Department of Mechanical Engineering, University of Newcastle, N.S.W. 2308, Australia
2 Génie des Procédés, Université de Marne la Vallée, 93166 Noisy le Grand Cedex, France
3 IRPHE, CNRS/Université d'Aix-Marseille - 13003 Marseille, France
Accepted: 27 November 1996
The relationship between fourth-order moments of and , the longitudinal- and transverse-velocity increments, respectively, is examined in some detail in the context of local isotropy and internal intermittency. Measurements in a plane jet at a sufficiently large value of the turbulence Reynolds number indicate an inertial-range behaviour of the flatness factors of and that is in reasonable agreement with the lognormal hypothesis of Kolmogorov and the log-Poisson model. In the inertial range, the fourth-order structure function exhibits a moderately larger departure from local isotropy than the second-order structure function.
PACS: 05.40.+j – Fluctuation phenomena, random processes, and Brownian motion / 05.45.+b – Theory and models of chaotic systems / 47.27.Gs – Isotropic turbulence; homogeneous turbulence
© EDP Sciences, 1997