Flight Experiments on Swept-Wing Roughness Receptivity: Validation Data for Modeling and Computations

Abstract

Micron-sized, spanwise-periodic Discrete Roughness Elements (DREs) were applied to the leading edge of a 30-degree swept-wing. The test article was attached vertically to the port wing of a Cessna O-2A aircraft and operated at a chord Reynolds number of 6.5 to 7.5 million. With a polished leading edge, 80% laminar flow was observed corresponding to N-factors greater than 12. Critically space DREs were applied a the leading edge to excite the crossflow instability and move transition forward. In this case, calibrated, multi-element hotfilm sensors were used to measure disturbance wall shear stress. The roughness height was varied from 0 to 50 microns both in the positive (bumps) and negative (dimples) sense. Thus, the disturbance amplitude variations were determined as a function of modulated DRE heights.

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Document Details

Document Type
Technical Report
Publication Date
Sep 22, 2010
Accession Number
ADA564004

Entities

People

  • William S. Saric

Organizations

  • Texas A&M University

Tags

Communities of Interest

  • Air Platforms
  • Materials and Manufacturing Processes
  • Sensors

DTIC Thesaurus Topics

  • Aircrafts
  • Boundary Layer
  • Climate Change
  • Computational Fluid Dynamics
  • Flow
  • Fluid Mechanics
  • Laminar Flow
  • Leading Edges
  • Measurement
  • Mechanics
  • Pressure Distribution
  • Pressure Gradients
  • Reynolds Number
  • Safety Analysis
  • Shear Stresses
  • Swept Wings
  • Three Dimensional

Fields of Study

  • Physics

Readers

  • Aerosol Science/Aerosol Physics
  • Atmospheric Science / Meteorology, specifically Wind Wave Turbulence.
  • Fluid Mechanics and Fluid Dynamics.

Technology Areas

  • Space
  • Space - Hall-Effect Thruster