Tilting Shear Layers in Coastal Flows
Abstract
ABSTRACT The "tilting shear layer," in which horizontal shear interacts with lateral density contrasts occurs frequently in strongly time-dependent flows in the coastal ocean including estuarine inflows and outflows, separating flows around headlands and islands, and merging flows in morphologically complex regions such as tidal inlets and fringing reef systems. The resulting buoyancy-driven flow results in tilting and intense stretching of the shear-flow vortices and ultimately a breakdown of the flow leading to strongly enhanced vertical mixing despite the fact that the gravity-driven flow by itself increases the vertical stratification. We propose to expand previous theoretical and numerical modeling (using DNS and LES) to incorporate more realistic conditions including variable topography, vertical stratification in each stream, bottom drag and rotation. These factors will be explored individually and in combination as the results of the modeling and FLEAT DRI dictate, with the goal of understanding conditions that amplify the surface vorticity expression, the vertical velocities, and the downstream vertical and horizontal mixing. Parameter regimes relevant to general coastal situations and those specific to the FLEAT DRI will be considered.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Aug 12, 2016
- Source ID
- N000141512242
Entities
People
- Karl Helfrich
Organizations
- Office of Naval Research
- United States Navy
- Woods Hole Oceanographic Institution