Turbulence: Two-Dimensional
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- Gregory Falkovich*, Physics of Complex Systems, Weizmann Institute of Science, Rehovot , Israel
- Michael Shats, The Australian National University, Canberra, Australia
Dr. Gregory Falkovich accepted the invitation on 13 October 2010
Introduction
Fluids naturally tend to form layers. Flows in layers can be often considered two-dimensional. When the fluid velocity \(v\) is in the plane, then the vorticity \(\omega=\nabla\times v\) has only one component (perpendicular to the plane) i.e. can be considered a scalar. In an fluid (without friction), Kelvin theorem states that the vorticity of any fluid element is conserved. As a result, two-dimensional flows possess an infinity of local conservation laws, given by arbitrary functions of vorticity, in addition to the kinetic energy.
Turbulence beyond fluids
Turbulence is a state of a system with many degrees of freedom deviated far from equilibrium. Such states exist not only in fluids.
