|dc.description.abstract||The present work was focused on study and application of active flow control methods to
alleviate the wake turbulence problem in commercial aircraft. Sinusoidal perturbations were
introduced into the tip vortex generated off one of the wings in a two wing system. Various
forcing frequencies and oscillation amplitudes were investigated in a towing tank facility.
Measurement techniques included invasive and non-invasive methodologies such as flow
visualization, hot film anemometry and particle image velocimetry (PIV).
Tilting of the plane of the vortices under forcing conditions was observed. The initiation
of long-wave Crow instability was observed. This was also confirmed by flow visualization
results. For 20Hz forcing frequency, elliptical deformation of the core for both the vortices was
observed. This was an indication of short wave Elliptic instability. When perturbed at a particular
frequency and amplitude, the overall system showed earlier onset of instabilities.||en_US