Accession Number : AD0425830

Title :   DECAY OF ISOTROPIC TURBULENCE IN THE DIRECTINTERACTION APPROXIMATION,

Corporate Author : NEW YORK UNIV N Y

Personal Author(s) : Kraichnan,Robert H.

Report Date : NOV 1963

Pagination or Media Count : 48

Abstract : The direct-interaction equations for the decay of isotropic turbulence are integrated numerically with initial spectra of several shapes and initial Reynolds values of R less than or in the vicinity of 40. Results are presented for the evolution with time of total energy, dissipation, energy transfer, skewness factor, and other integral quantities, together with the associated wavenumber spectra. Similarity and self-preservation features of the evolving spectra are exhibited. The results are compared with grid-turbulence measurements by Stewart and Townsend. Results are also given for the timecorrelation of the total velocity at a fixed point in space and for the time-correlation and response functions of individual wavenumber modes. (Author)

Descriptors :   (*TURBULENCE, NUMERICAL METHODS AND PROCEDURES), TURBULENT BOUNDARY LAYER, TIME, ENERGY, EQUATIONS, STATISTICAL DISTRIBUTIONS, NUMERICAL ANALYSIS, VELOCITY, REDUCTION, INTERFERENCE, REYNOLDS NUMBER, STATISTICAL ANALYSIS

Distribution Statement : APPROVED FOR PUBLIC RELEASE