Annualmeeting:2017 CSDMS meeting-046
Turbulence-resolving Two-Phase Flow Simulations of Wave- and Current Supported Turbidity Flows
[[Image:|300px|right|link=File:]]Wave- and current-supported turbidity currents are new class of turbidity flows that has been discovered over the last three decades. Its significance as a carrying agent of fine sediments over low-gradient shelves has been recognized with growing evidence. Due to their vertical length scales, which are on the order of decimeters, understanding the full range of mechanisms that are responsible for and/or affect these currents cannot proceed without turbulence-resolving numerical simulations and/or high-resolution sensor deployment in a laboratory/field experiments. In this talk the culmination of two-phase, turbulence-resolving simulations, i.e. Direct Numerical Simulations (DNS), of wave- and alongshore current-supported fine sediment turbidity currents across mild bathymetric slopes will be presented. Simulation results show that such turbidity currents follow a logarithmic velocity profile across the shelf whose parameters depend on the sediment concentration, across-shore bathymetric slope, and Reynolds number while it is independent of the settling velocity of the sediments. The numerical simulations also provide significant insights on modelling these turbidities in a regional-scale model which can be used to estimate the location of mud depocenters and the dynamics of submarine geomorphology such as in the clinoform development at the continental margin.