Flight Experiments on Local and Global Effects of Surface Roughness on 2-D and 3-D Boundary-Layer Stability and Transition

Abstract

The work cumulated in a series of laminar-turbulent transition flight-text experiments on a swept wing with the goal of validating the spanwise-periodic distributed roughness elements (DRE) technology in a Reynolds number range applicable to SensorCraft technology. Phase I of the program measured freestream turbulence levels that were nominally 0.05% to 0.06% of the freestream speed and thus established the suitability of the flight environment for the laminarization flights. Phase II of the program did the baseline transition measurements on the airfoil, i.e., with and without DRE technology. The region of laminar flow was extended from 30% to 60% chord at a chord Reynolds number of Rec=8 million and sweep angle of 30 deg.

Open PDF

Document Details

Document Type
Technical Report
Publication Date
Jul 21, 2008
Accession Number
ADA484737

Entities

People

  • William S. Saric

Organizations

  • Texas A&M University

Tags

Communities of Interest

  • Space

DTIC Thesaurus Topics

  • Air Force Research Laboratories
  • Amplitude
  • Boundary Layer
  • Boundary Layer Transition
  • Computational Fluid Dynamics
  • Flow
  • Fluid Dynamics
  • Fluid Mechanics
  • Hypervelocity Flow
  • Laminar Flow
  • Reynolds Number
  • Surface Roughness
  • Swept Wings
  • Three Dimensional
  • Turbulence
  • Turbulent Flow
  • Turbulent Mixing

Fields of Study

  • Physics

Readers

  • Aerodynamics/Aeronautics.
  • Defense Technology Research and Development.
  • Fluid Mechanics and Fluid Dynamics.