Accession Number : ADP005011

Title :   Velocity and Turbulence Measurements in Dynamically Stalled Boundary Layers on an Oscillating Airfoil,

Corporate Author : VRIJE UNIV BRUSSELS (BELGIUM) DEPT OF FLUID MECHANICS

Personal Author(s) : Ruyck,J. de ; Hirsch,C.

Report Date : NOV 1985

Pagination or Media Count : 13

Abstract : Detailed velocity and turbulence properties in the dynamically stalled boundary layer of an oscillating NACA 0012 airfoil have been measured. This airfoil oscillates around an axis at 25% distance from the leading edge with a sinusoidal motion. Measurements are performed at eight chordwise positions, in non stalled, stall onset and deep stalled flow conditions. Instantaneous detailed flow and turbulence patterns of the periodic separation vortex are presented and discussed. Corresponding terms of the turbulent energy balance are derived and compared with flat plate boundary layer data. In particular, negative turbulent energy production is observed during the vortex development.

Descriptors :   *STALLING, *BOUNDARY LAYER, VORTICES, AIRFOILS, OSCILLATION, FLOW SEPARATION, VELOCITY, TURBULENCE, PITCH(MOTION), BELGIUM

Distribution Statement : APPROVED FOR PUBLIC RELEASE