Mixing and entrainment in hydraulically driven stratified sill flows

Turbulent mixing of stratified flows

A mathematical model for turbulent mixing of stratified, sheared flows is developed and explored. Two applications are emphasized, one to the dynamics of the ocean well–mixed layer, and another to the analysis of the stability of equilibrium profiles away from boundaries.

Turbulent mixing in strongly stratified shear flows

Motivated by the importance of irreversible mixing in geophysical and environmental flows, we seek to understand the dependence of its efficiency under strongly stratified conditions through a seris of direct numerical simulation of Holmboe wave instability under various initial conditions. Our numerical findings demonstrate that while mixing is enhanced when the density layer is much sharper t...

A Non-Fickian Mixing Model for Stratified Turbulent Flows

The long term goal of this project is to develop a better understanding of oceanic processes in the range of 100 m to 10 km, in the so-called submesoscale range. In particular, it is important to explore and find out whether and what type of submesoscale instabilities exist, how they are connected to both larger scale and smaller scale motions, and to what extent they influence transport proces...

Currents in Stratified Water Bodies 1: Density-Driven Flows

Diffusion and mixing in gravity-driven dense granular flows.

We study the transport properties of particles draining from a silo using imaging and direct particle tracking. The particle displacements show a universal transition from superdiffusion to normal diffusion, as a function of the distance fallen, independent of the flow speed. In the superdiffusive (but sub-ballistic) regime, which occurs before a particle falls through its diameter, the displac...