Accession Number : ADA182399

Title :   Organized Structures in a Supersonic Turbulent Boundary Layer,

Corporate Author : PRINCETON UNIV NJ DEPT OF MECHANICAL AND AEROSPACE ENGINEERING

Personal Author(s) : Spina, Eric F ; Smits, Alexander J

PDF Url : ADA182399

Report Date : Feb 1986

Pagination or Media Count : 186

Abstract : Experiments were conducted on organized structures in turbulent boundary layers by examining their behavior in a compressible flow. Large-scale structures, inclined at 45deg. to the wall, were found to fill the height of the boundary layer. As they were convected downstream, these structures retained a great deal of their shape and character, and preserved their identity for at least 1.5 delta--where delta is the height of the largest contributing eddy in its hierarchy. However, the spanwise extent of the structures was limited. The individual events, whether pressure or mass flow, were similar to each other and to the average event, and they were very energetic. In general the positive mass-flow events had a higher frequency content and were larger in amplitude than the negative events. It would appear that the effect of compressibility on the large-scale motions is very small. Certainly, there are more similarities than differences between the events found in this compressible flow and those observed in incompressible flow and those observed in incompressible boundary layers. These similarities are clearly shown by comparing the structure angles and the conditionally-averaged results.

Descriptors :   *COMPRESSIBLE FLOW, *SUPERSONIC FLOW, *TURBULENT BOUNDARY LAYER, BOUNDARY LAYER FLOW, HIERARCHIES, BOUNDARY LAYER, INCOMPRESSIBILITY, MOTION, MASS FLOW, ANGLES, AMPLITUDE, STRUCTURES, EDDIES(FLUID MECHANICS), AMPLITUDE, STRUCTURAL PROPERTIES, FREQUENCY, ANGLES, BOUNDARY LAYER, COMPRESSIBLE FLOW, HIERARCHIES, INCOMPRESSIBILITY, INCOMPRESSIBLE FLOW, MASS FLOW, MOTION, STRUCTURES, SUPERSONIC FLOW, TURBULENT BOUNDARY LAYER

Subject Categories : Fluid Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE