Experimental Attenuation of a Trailing Vortex Inspired by Stability Analysis

Inspired by a parabolized stability analysis [1], higher-order wake instability modes are targeted via the actuation of a tensioned string in the mean-chord-plane just aft of the trailing edge of a NACA0012 half-wing at 5 degrees angle of attack and a chord based Reynolds number (Re-c) of 1.32 x 10(5). Stereoscopic Particle Image Velocimetry (SPIV) and a load cell are used to assess the effects of the control just downstream of the trailing edge and 6.5 chords downstream. The results reveal increased turbulence intensity in the wake that is engulfed into the vortex during its formation, and a reduction in the time-averaged streamwise vorticity downstream with minimal loss of lift, providing evidence of the possibility of exciting instability modes for subsequent attenuation of the vortex farther downstream.