LDA Measurements of the Unsteady Near Wake Behind an Airfoil Undergoing Transient and Periodic Pitching Motions,

Abstract

This paper presents results of two-dimensional LDA measurements performed in the near wake of an airfoil undergoing stepwise motions and saw-tooth periodic motions with incidence variations from -1 deg to 25 deg, revealing dynamic stall features. The driving mechanism used here is a new one, based on an automatic apparatus, which allows the airfoil to be put into a wide range of periodic or transient pitching and/or heaving motions. Time-dependent velocity traces for the two components, streamwise velocity profiles, evolution of the semi wake thickness and vector velocity field are discussed. These results, obtained at a Reynolds number of 267000, are compared to those corresponding to steady flow. (Author)

Document Details

Document Type
Technical Report
Publication Date
Jul 23, 1992
Accession Number
ADP008953

Entities

People

  • F. Wietrich
  • G. Koerber
  • P. Wernert

Organizations

  • Technical University of Lisbon

Tags

DTIC Thesaurus Topics

  • Computers
  • Flow
  • Fluid Dynamics
  • Fluid Mechanics
  • Fluid Statics
  • Hydrodynamics
  • Measurement
  • Mechanics
  • Reynolds Number
  • Statics
  • Steady Flow
  • Stratified Fluids
  • Two Dimensional

Fields of Study

  • Physics

Readers

  • Aerodynamics/Aeronautics.
  • Control Systems Engineering.
  • Fluid Dynamics.