arXiv 1402.48352014-06-27math.DSphysics.flu-dynphysics.geo-ph

How coherent are the vortices of two-dimensional turbulence?

Mohammad Farazmand, George Haller

备注：: revised version

英文摘要：

We use recent developments in the theory of finite-time dynamical systems to objectively locate the material boundaries of coherent vortices in two-dimensional Navier--Stokes turbulence. We show that these boundaries are optimal in the sense that any closed curve in their exterior will lose coherence under material advection. Through a detailed comparison, we find that other available Eulerian and Lagrangian techniques significantly underestimate the size of each coherent vortex.

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