POD analysis of near-wake structures of an elliptic cylinder adjacent to a free surface

Abstract

The POD (Proper Orthogonal Decomposition) method was used to investigate the near-wake behind an elliptic cylinder located under a free surface. For two different depths of cylinder submergence, the first four eigenmodes of the flow field were calculated and their structures were analyzed. The first four eigenmodes reveal the details about the global mean flow structure, with the large-scale structure being mainly related to the most energetic flow motion. The convergence of accumulated eigenvalues shows a slight dependence on the number of instantaneous velocity fields used in POD analysis.