Flow Separation Induced by Periodic Aerodynamic Interference

Abstract

Analysis of experimental surface pressure distributions on an NACA 0012 airfoil has revealed four flow states: attached, separated, borderline, and dynamically separated. The important parameters that determine the flow state are Reynolds number, reduced frequency, airfoil angle of attack, and surface condition at the leading edge. Testing was done at Re=700,000, .5<=k<=6.4, and 0<=alpha<=18 degrees. For this flow the dynamically separated state takes the form of an alternation between attached and separated flow. It has a period that ranges from 1 to 30 times that of the unsteady perturbation. In the separated state a convected surface pressure disturbance was identified, and found to propagate downstream from a location near the leading edge at a phase speed of 1/3 to 1/2 that of the freestream velocity.

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Document Details

Document Type
Technical Report
Publication Date
Jan 01, 1984
Accession Number
ADP004174

Entities

People

  • C. M. Vaczy
  • E. E. Covert
  • P. F. Lorber

Organizations

  • Massachusetts Institute of Technology

Tags

Communities of Interest

  • Materials and Manufacturing Processes
  • Sensors
  • Space

DTIC Thesaurus Topics

  • Air Force
  • Airfoils
  • Boundary Layer
  • Computational Fluid Dynamics
  • Flow Fields
  • Flow Visualization
  • Fluid Flow
  • Leading Edges
  • Phase Velocity
  • Pressure Distribution
  • Reynolds Number
  • Standing Waves
  • Surface Properties
  • Trailing Edges
  • Transducers
  • Turbines
  • Unsteady Flow

Fields of Study

  • Physics

Readers

  • Brain and Cognitive Science; Experimental Psychology; Cognitive Neuroscience
  • Fluid Mechanics and Fluid Dynamics.