Article ID Journal Published Year Pages File Type
1721866 Journal of Hydrodynamics, Ser. B 2016 6 Pages PDF
Abstract

The Casimir invariants of the 2-D turbulence are investigated by the lattice Boltzmann method. A coarse-graining approach is used, that allows to resolve the flux of the Casimir invariant in scale and in space. It is found that the flux of the enstrophy cascades to small scales and the direction cascade of the energy flux is upscaled. Moveover, the probability distribution function (PDF) of the enstrophy flux gives a clear evidence that the enstrophy cascades to smaller scales. Finally, the behavior of the cascade of the high-order Casimir invariants Zn is discussed. The flux of the fourth-order Casimir invariant Z4 cascades to small scales. The flux of Zn   has a logarithmic relationship with the scale, that is, ΠlZn∼lζn(n=2,4,6).

Related Topics
Physical Sciences and Engineering Engineering Ocean Engineering
Authors
, ,