
Accession Number : AD0628541
Title : DISPERSION OF PARTICLE PAIRS IN HOMOGENEOUS TURBULENCE.
Descriptive Note : Research rept.,
Corporate Author : KRAICHNAN (ROBERT H) PETERBOROUGH N H
Personal Author(s) : Kraichnan,Robert H.
Report Date : FEB 1966
Pagination or Media Count : 25
Abstract : The relative dispersion of particle pairs in homogeneous turbulence is treated by the Lagrangianhistory directinteraction closure approximation for a conserved scalar field. Richardson's diffusion equation emerges, with the sole difference that the eddy diffusivity depends on the duration of the dispersion as well as on particle separation. The diffusivity tensor is evaluated in the inertial range, and the probability distribution for the separation distance of a particle pair is computed for longtime, inertialrange dispersion. From this solution, numerical values are obtained for the dimensionless constants in Richardson's law for meansquare separation distance and Oboukhov's scalarfield inertialrange spectrum law. An inequality relating these two constants is inferred from qualitative considerations, without use of the closure approximation. (Author)
Descriptors : (*TURBULENCE, DIFFUSION), (*DIFFUSION, TURBULENCE), PARTICLES, SCATTERING, FLUID MECHANICS, NUMERICAL ANALYSIS
Subject Categories : Fluid Mechanics
Distribution Statement : APPROVED FOR PUBLIC RELEASE