Collections > Electronic Theses and Dissertations > Procedures for the identification of coherent structures in oscillatory and pulsating flows over a wavy bottom

Oscillatory flows over a wavy bottom play an important role in sediment dynamics, coastal circulation and bottom - water column biogeochemical interactions. The most important process that controls the energy and mass flux in such flows is the generation, advection and dissipation of coherent structures. This thesis gives a working definition of a coherent structure in an instantaneous and averaged flow and compares several identification methods using velocity and pressure fields obtained from computer simulations using a Large Eddy Simulation (LES) numerical scheme. The effectiveness of each identification method is assessed for several flows with different Reynolds number and relevant physical properties of each flow, obtained from the study of such coherent structures, are described.