Global Pressure and Temperature Surface Measurements on a NACA 0012 Airfoil in Oscillatory Compressible Flow at Low Reduced Frequencies

Abstract

A co-axial contra-rotating helicopter in forward flight has stall mechanisms that are intrinsically different from those on a traditional helicopter. Traditional helicopters need a cyclic pitch mechanism to balance the rotor lift about each rotation, which leads to dynamic stall from the rapid oscillations in pitch. Co-axial contra-rotating helicopters, which have a fixed pitch about each cycle, encounter a sinusoidal oscillation in Mach number with the mean velocity seen as the rotational velocity while the half amplitude is equal to the forward flight speed. The fluid dynamic mechanism limiting the forward flight speed is entirely different from that of traditional dynamic stall studies. This work sets out to design, create, and study the application of an oscillatory compressible flow field on a NACA 0012 airfoil in order to experimentally model this flow situation.

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Document Details

Document Type
Technical Report
Publication Date
Jan 01, 2012
Accession Number
ADA563389

Entities

People

  • Christopher D. Jensen

Organizations

  • Ohio State University

Tags

Communities of Interest

  • Air Platforms
  • Energy and Power Technologies
  • Space

DTIC Thesaurus Topics

  • Accuracy
  • Boundary Layer
  • Compressible Flow
  • Computational Fluid Dynamics
  • Flight Speeds
  • Flow Fields
  • Flow Visualization
  • Fluid Dynamics
  • Fluid Flow
  • Frequency
  • Mach Number
  • Measurement
  • Pressure Distribution
  • Pressure Measurement
  • Three Dimensional
  • Two Dimensional
  • Wave Propagation

Fields of Study

  • Physics

Readers

  • Aerodynamics/Aeronautics.
  • Aerospace Engineering
  • Computational Fluid Dynamics (CFD)