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Article

Infrared Reynolds number dependency of the two-dimensional inverse energy cascade

Authors: Vallgren, 
Document Type: Article
Pubstate: Published
Journal: Journal of Fluid Mechanics
Volume: 667   463-473
Year: 2011

Abstract

High-resolution simulations of forced two-dimensional turbulence reveal that the inverse cascade range is sensitive to an infrared Reynolds number, Re? = kf/k?, where kf is the forcing wavenumber and k? is a frictional wavenumber based on linear friction. In the limit of high Re?, the classic k?5/3 scaling is lost and we obtain steeper energy spectra. The sensitivity is traced to the formation of vortices in the inverse energy cascade range. Thus, it is hypothesized that the dual limit Re? ? ? and Re? = kd/kf ? ?, where kd is the small-scale dissipation wavenumber, will lead to a steeper energy spectrum than k?5/3 in the inverse energy cascade range. It is also found that the inverse energy cascade is maintained by non-local triad interactions.