Accession Number : AD0601041

Title :   REYNOLDS STRESS NEAR A FLEXIBLE SURFACE RESPONDING TO UNSTEADY AIR FLOW.

Corporate Author : BOLT BERANEK AND NEWMAN INC CAMBRIDGE MASS

Personal Author(s) : Williams,J. E. Ffowcs

Report Date : 03 JUN 1964

Pagination or Media Count : 27

Abstract : The paper studies the way in which Reynolds stresses near the flow boundary are influenced by surface response. The technique of analysis is based on that developed by Lin (Proc. Nat. Acad. Sciences, 40:741, 1954) to study the Reynolds stresses induced by viscous action in the vicinity of the surface. The technique is generalized to allow for a random surface motion, such as might be induced by turbulent flow, but the analysis is restricted to a two-dimensional surface profile. The most interesting outcome of the analysis is that the Reynolds stress assumes a negative sense close to the surface whenever the phase speed of the perturbation exceeds the speed of free suface waves. The layer of fluid close to the mean position of the surface may then tend to starve the turbulent eddies of their energy supply and may lead to a reduction in the turbulence level. (Author)

Descriptors :   (*TURBULENT BOUNDARY LAYER, STRESSES), BOUNDARY LAYER, STABILITY, SURFACES, MEMBRANES, VIBRATION, NOISE, VORTICES, REYNOLDS NUMBER, GAS FLOW

Distribution Statement : APPROVED FOR PUBLIC RELEASE