Vorticity characterization in a turbulent boundary layer using PIV and POD analysis

We investigate coherent structures in turbulent boundary layer flow using Particle Image Velocimetry(PIV) technique. Flow coherent patterns have been identified and characterized using Proper Orthogonal Decomposition technique, applied to the instantaneous vorticity fields. Spatial characteristics, previously reported in the literature, such as non-dimensional length scale (x + 1000), and the average expansion angle ( 9 ), have been found from linear combination of three first POD modes.