Experimental investigation of the leading-edge flow of a dynamically pitching airfoil

The primary objective of this paper is to provide high fidelity, high resolution mean and turbulent flowfield data for a dynamically pitching NACA 0012 wing at realistic flight (helicopter) Mach and Reynolds numbers. Results are presented for the wing flapping in Light Dynamic Stall (LDS) region at a mean angle of attack of 10, oscillation amplitude of 10, and a reduced frequency (k) of 0.1. An experimental campaign using high-resolution Particle Image Velocimetry (PIV) was performed on a large scale (c=0.45 m) dynamically pitching NACA 0012 wing with Rec = 2 106. The focus of the present study was the leading edge region, where the PIV data acquisition concentrated on the first 10- 15% of the airfoil. Mean velocity and turbulent stress profiles are presented. Analyses of the turbulent flow structure provided new insights into the leading-edge Reynolds shear stress structure and the turbulent transport processes. Copyright 2008 by the American Institute of Aeronautics and Astronautics, Inc.

Experimental investigation of the leading-edge flow of a dynamically pitching airfoil Conference Paper