Accession Number : AD0609460

Title :   AN EXPERIMENTAL STUDY OF TURBULENCE IN A DRIVEN VORTEX,

Corporate Author : AERONAUTICAL RESEARCH ASSOCIATES OF PRINCETON INC N J

Personal Author(s) : Donaldson,Colman duP. ; Williamson,Guy G.

Report Date : JUL 1964

Pagination or Media Count : 44

Abstract : Measurements have been made at two rotational speeds of the mean motion and turbulence levels within a shallow vortex chamber that has a rotating porous wall as an outer boundary. Very nominal levels of turbulence ( 2 to 3 per cent ) were observed on the central plane of these vortices while a significant portion of the mass flow through the vortex was observed to pass through the end wall boundary layers. A fairly high level of turbulence was then introduced into this vortex chamber by means of a grid of axially aligned bars at the outer rim of the vortex. This high level of turbulence was observed to decay rapidly to a relative level of intensity of about 6 percent, indicating that for tangential Reynolds numbers up to at least 100000, the flow with a driven vortex is stable with respect to the introduction of turbulence. The results obtained corroborate Kendall's findings, namely that the primary cause of the degradation of the performance of a confined vortex is the leakage of mass flux through the boundary layers on the end walls of the vortex chamber. (Author)

Descriptors :   (*VORTICES, TURBULENCE), (*TURBULENCE, VORTICES), VORTEX GENERATORS, FLUID FLOW, ROTATION, REYNOLDS NUMBER

Distribution Statement : APPROVED FOR PUBLIC RELEASE