Thermal and Flow Structures in Accelerated/Decelerated Transitional Boundary Layers

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.

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Document Details

Document Type
Technical Report
Publication Date
Feb 15, 1998
Accession Number
ADA339013

Entities

People

  • Ting Wang

Organizations

  • Clemson University

Tags

Communities of Interest

  • Energy and Power Technologies

DTIC Thesaurus Topics

  • Boundary Layer
  • Boundary Layer Flow
  • Computational Fluid Dynamics
  • Computational Science
  • Databases
  • Energy Transfer
  • Flow Visualization
  • Fluid Dynamics
  • Fluid Flow
  • Fluid Mechanics
  • Heat Transfer
  • Measurement
  • Mechanical Engineering
  • Mechanics
  • Pressure Gradients
  • Test Facilities
  • Three Dimensional

Fields of Study

  • Physics

Readers

  • Fluid Dynamics.
  • Thermal Physics or Thermal Science.