Abstract
The vortex wake of a two-dimensional oscillating airfoil is investigated experimentally by the use of computer aided flow visualization and measurement techniques. The model airfoil of a NACA 0012 cross-section is set at a large incidence in excess of the critical angle of attack and subjected to a harmonic oscillation in pitch around the one-third chord axis. Some measurement is attempted to estimate instantaneous distribution of velocity and vorticity and the relevant evaluation is made as to circulation of wake vortices. On the basis of these results, the vortex wake characteristics in dependence on the reduced frequency is briefly discussed.
