Interaction of a finite span synthetic jet with a streamwise vortex

Wind tunnel experiments were conducted to determine the effects of a synthetic jet (SJ) on a streamwise vortex using stereo particle image velocimetry. The streamwise vortex was produced by vortex generators (VG) of varying immersion ratios with respect to the laminar boundary layer thickness placed upstream of a synthetic jet that was skewed and pitched at 45 degrees. Time and phase-averaged SPIV data were acquired with the VG alone, SJ alone with blowing ratios of 1.0 and 0.5 and were compared to a case where both the SH and the VG were present. The time averaged measurements show that the SJ is able to bring the streamwise vortex closer to the wall and, when aligned spanwise with a vortex, interacts favorably with it, increasing its circulation, while also increasing the streamwise velocity of the vortex core. These increases lead to a delay in the dissipation or breakdown of the vortex structure further downstream. An increase in the blowing ratio resulted in even stronger effects. Additional experiments were conducted with the VG placed off center from the SJ and will be presented.