Coherent Structures in a Three-dimensional Chaotic Potential Flow

Central to understanding all chaotic advection processes is the nature of periodic points and their associated coherent structures. They provide a framework upon which transport dynamics play out. We show that degenerate points which are often overlooked play an important role in shaping this framework and the overall flow. In particular for the three-dimensional Reoriented Potential Mixing (3DRPM) flow the degenerate points create local stable regions that prevent global chaos.