Accession Number : AD0686260

Title :   THE DISTORTION OF TURBULENCE BY IRROTATIONAL PLANE STRAIN,

Corporate Author : WINDSOR UNIV (ONTARIO) DEPT OF MECHANICAL ENGINEERING

Personal Author(s) : Tucker,H. J. ; Reynolds,A. J.

Report Date : 08 DEC 1967

Pagination or Media Count : 17

Abstract : The experiments extend those of Townsend which form the basis of his model of free turbulence. Here straining is carried to a strain ratio of 6:1, while Townsend's straining went only to 4:1. Two kinds of distorting ducts are used to produce the uniform mean strain applied to initially nearly isotropic grid turbulence. The results differ from Townsend's in that (1) a considerably higher degree of anisotropy is achieved, Townsend's measure of anisotropy attaining values up to 0.6, rather than the maximum of 0.42 he found; (2) there is no evidence that an equilibrium structure is attained; and (3) the strained turbulence rapidly becomes less anisotropic when the straining ceases. It is found to be possible to predict the variation of the total turbulence energy using rapid-distortion theory with a correction for decay. However, the individual components cannot be accurately predicted in this way. (Author)

Descriptors :   (*TURBULENCE, *STRAIN(MECHANICS)), SHEAR STRESSES, DUCTS, DISTORTION, NUMERICAL ANALYSIS, CANADA

Subject Categories : Fluid Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE