Vortex Pair Interaction with Polymer Layer

This paper investigates the interaction of vortex pairs with a layer of polymeric fluid, a problem distinct from traditional vortex-boundary interactions in Newtonian fluids. It explores how polymer concentration, relaxation time, layer thickness, and polymer extension affect energy and enstrophy. The key finding is that the polymer layer can not only dissipate vortical motion but also generate new coherent structures, leading to transient energy increases and, in some cases, complete dissipation of the primary vortex. This challenges the conventional understanding of polymer-induced drag reduction and offers new insights into vortex-polymer interactions.