Accession Number : ADA312815

Title :   Turbulent Boundary Layers in Subsonic and Supersonic Flow (les Couches limites turbulentes dans les ecoulements subsoniques et supersoniques),

Corporate Author : ADVISORY GROUP FOR AEROSPACE RESEARCH AND DEVELOPMENT NEUILLY-SUR-SEINE (FRAN CE)

Personal Author(s) : Saric, William S.

PDF Url : ADA312815

Report Date : JUL 1996

Pagination or Media Count : 83

Abstract : Current research on the structure of zero pressure gradient, flat plate turbulent boundary layers is reviewed. The behavior of boundary layers in subsonic and supersonic flow is discussed, with a particular emphasis on scaling laws with respect to Reynolds number and Mach number. For subsonic flows, it is shown that for the mean flow the classic arguments on inner and outer layer similarity hold extremely well over a large range of Reynolds numbers (approximately 350 < Re > 210,000), and the overlap region is well established over the same region. In contrast, the Reynolds number can have a significant effect on the level of the maximum turbulence stresses, and the location of that maximum in the boundary layer. In particular, the streamwise scaling of the outer-layer is rather sensitive, where the scale increases with the Reynolds number. For supersonic flows with moderate Mach number, it appears that the direct effects of compressibility on wall turbulence are rather small: the most notable differences between subsonic and supersonic boundary layers may be attributed to the variation in fluid properties across the layer. However, certain characteristics cannot be collapsed by simple scaling. Among other observations, there exists strong evidence to indicate that the streamwise length scales are reduced significantly by increasing Mach number.

Descriptors :   *TURBULENT BOUNDARY LAYER, *SUBSONIC FLOW, *SUPERSONIC FLOW, HEAT TRANSFER, NATO, STRESS ANALYSIS, TURBULENCE, EDDIES(FLUID MECHANICS), COMPUTATIONAL FLUID DYNAMICS, COMPRESSIBLE FLOW, SUBSONIC CHARACTERISTICS, MACH NUMBER, SUPERSONIC CHARACTERISTICS, FREE STREAM, VISCOUS FLOW, PRESSURE DISTRIBUTION, REYNOLDS NUMBER, INCOMPRESSIBLE FLOW, SKIN FRICTION, STAGNATION TEMPERATURE.

Subject Categories : Fluid Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE