title: Upscale energy transfer and flow topology in free-surface turbulence.
abstract: Free-surface turbulence, albeit constrained onto a two-dimensional space, exhibits features that barely resemble predictions of simplified two-dimensional modeling. We demonstrate that, in a three-dimensional open channel flow, surface turbulence is characterized by upscale energy transfer, which controls the long-term evolution of the larger scales. We are able to associate downscale and upscale energy transfer at the surface with the two-dimensional divergence of velocity. We finally demonstrate that surface compressibility confirms the strongly three-dimensional nature of surface turbulence.
authors: Department of Electrical, Management and Mechanical Engineering, University of Udine, 33100, Udine, Italy.
authors: Salvatore
authors: S
authors: Lovecchio
authors: Department of Electrical, Management and Mechanical Engineering, University of Udine, 33100, Udine, Italy.
authors: Francesco
authors: F
authors: Zonta
authors: Department of Electrical, Management and Mechanical Engineering, University of Udine, 33100, Udine, Italy.|Department of Fluid Mechanics, CISM, 33100, Udine, Italy.
authors: Alfredo
authors: A
authors: Soldati