Global characterization of oscillating grid turbulence in homogeneous and two-layer fluids, and its implication for mixing at high Peclet number

Abstract

For oscillating grid turbulence (OGT) in homogeneous fluids, the turbulence intensity decreases with the distance to the vibrating grid used to generate the forcing, and it is usually described in terms of depth profiles of turbulent quantities (kinematic energy, integral length scale, and eddy viscosity) . Here we propose revised parametric laws for these quantities in homogeneous fluid, and present new results for a two-layer fluid for which the turbulent quantities are strongly altered by the fluid interface. In the case of a two-layer fluid, we also investigate the mixing and discuss the role of turbulent flow properties at the interface as well as weak mean flow features.

Topics & Concepts