Fully Developed Turbulence with Diminishing Mean Vortex Stretching and Reduced Intermittency

Abstract

Fluid turbulence determines drag characteristics of land/air/seaborne vehicles, mixing and reaction rates in chemical reactors, industrial mixers, burners, and complex non-equilibrium phenomena such as flame reignition and extinction. It is central to weather and environmental predictions, cloud precipitation and albido, atmospheric and oceanic transport and ocean-atmosphere interactions. Central to three-dimensional turbulent fluid flows is the vortex-stretching mechanism which generates the multitude of eddy sizes that make simulations prohibitive. Studies aiming at understanding the intrinsic dynamics of fully developed turbulence have concentrated on homogeneous isotropic turbulence in the wind tunnel [1, 2, 3], where the turbulence dynamics result purely from the vortex-stretching mechanism in isolation. Here we report the discovery of a new type of homogeneous isotropic three-dimensional fluid turbulence where the average vortex stretching diminishes and the level of small-scale intermittency remains constant as the turbulence intensifies. Hence, the deepest of all turbulence properties, vortex stretching and intermittency, can be tampered with.