Accession Number : ADA339013

Title :   Thermal and Flow Structures in Accelerated/Decelerated Transitional Boundary Layers

Descriptive Note : Final rept.

Corporate Author : CLEMSON UNIV SC DEPT OF MECHANICAL ENGINEERING

Personal Author(s) : Wang, Ting

PDF Url : ADA339013

Report Date : 15 FEB 1998

Pagination or Media Count : 146

Abstract : The objective of this program is to experimentally investigate the flow and thermal structures in transitional boundary layers with both favorable and adverse pressure gradients at elevated free-stream turbulence (FSTI, between 3% to 7%). The experiments were performed in a low speed, open-circuit, blowing type wind tunnel. A uniformly heated wall was used as the test surface. The experimental parameters (FSTI, roughness, and streamwise pressure gradients) were then systematically varied to study their individual and combined effects on the thermal and flow structures in the laminar and turbulent transition process. A specially designed miniature three wire probe was used to measure the flow and thermal structures in the boundary layer including the Reynolds stresses, Reynolds heat fluxes, turbulent Prandtl numbers, eddy diffusivities, and turbulent thermal diffusivities within the transitional and turbulent boundary layers. Conditional sampling techniques were applied to investigate the intermittent thermal and flow behaviors in the transitional boundary layers. Spectral analysis was conducted. The primary conclusions from each part of the investigation are summarized in this report Corresponding papers are attached for detailed information.

Descriptors :   *TURBULENCE, *THERMAL DIFFUSION, *BOUNDARY LAYER TRANSITION, *FREE STREAM, PRESSURE GRADIENTS, EDDIES(FLUID MECHANICS), TURBULENT BOUNDARY LAYER, VORTICES, FLOW FIELDS, THERMAL ANALYSIS, HEAT FLUX, REYNOLDS NUMBER, BOUNDARY LAYER FLOW, MOMENTUM TRANSFER, LAMINAR BOUNDARY LAYER, PRANDTL NUMBER, TURBULENT DIFFUSION.

Subject Categories : Fluid Mechanics
      Thermodynamics

Distribution Statement : APPROVED FOR PUBLIC RELEASE