GEORGE HALLER
Brown University
Division of Applied Mathematics
Brown University
Providence, RI 02912
http://www.cfm.brown.edu/people/haller/home.html
haller@cfm.brown.edu
Abstract:
It is well known that in two-dimensional turbulent fluid flows coherent structures tend to emerge. These structures have primarily been described based on instantenous Eulerian quantities, such as energy, vorticity, or enstrophy, all giving different answers for the exact location and properties of coherent structures. At the same time, in many industrial and geophysical flow problems the exact location of the boundaries of these structures, as well as their impact on mixing, is of fundamental importance. In this talk we describe new dynamical systems-based methods that do detect exact coherent structure boundaries in the Lagrangian sense. We survey applications to numerical and experimental data of relevance to geophysical turbulence and control of mixing in combustors. We also outline extensions to 3D fluid flows.