Vorticity in the turbulent flow above variously rough surfaces

Highly turbulent flows above variously rough surfaces were investigated by means of Time-Resolved Particle Image Velocimetry in a wind tunnel. Proper Orthogonal Decomposition was applied to both velocity and vorticity data in order to detect dominant features in the flow based on turbulent kinetic energy and enstrophy, respectively. While both the shape and location of the POD patterns exhibited similarity with other studies, a systematic inconsistency in terms of contribution from the features to the enstrophy between the previously published papers and our results were found.