Accession Number : ADA134230

Title :   An Investigation of Airfoil Dynamic Stall with Large Amplitude Motions.

Descriptive Note : Final rept. Jun 76-Jun 83,

Corporate Author : FRANK J SEILER RESEARCH LAB UNITED STATES AIR FORCE ACADEMY CO

Personal Author(s) : Francis,Michael S ; Keesee,John E ; Retelle,John P , Jr

PDF Url : ADA134230

Report Date : Oct 1983

Pagination or Media Count : 158

Abstract : The results of an experimental investigation of airfoil dynamic stall involving large amplitude pitching motions are described. The discussion is focused on constant pitch rate motion histories. Measurements of unsteady surface pressure distributions for both NACA 0012 and NACA 64 sub 1 A012(13) profiles have been employed to infer the onset and evolution of an energetic leading edge separation vortex over a wide range of flow and motion conditions. These data have also been integrated to provide estimates of the time histories of the lift, pressure drag and moment coefficients. The effectiveness of the various motions for achieving lift enhancement has been determined through the introduction of a dimensionless impulse parameter which accounts for both the magnitude and duration of the additional lift increment during the post-stall period. (Author)

Descriptors :   *Unsteady flow, *Airfoils, *Stalling, *Flow separation, *Pitch(Motion), Leading edges, Vortices, Pressure distribution, Lift, Augmentation, Coefficients, Moments, Mathematical models, Experimental design, Oscillation, Rates, Suction, Rigidity, Aerodynamics, Wind tunnel models

Subject Categories : Fluid Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE