Project Title: LES of coupled mixed-grain sand transport and morphodynamics induced by oscillatory flow over ripples and waves over perched beach configurations
Doctoral Candidate: Ioannis TSIPAS
Project Description: Coupled LES of 3D turbulent flow with mixed-grain sand transport (bed and suspended), and resulting bed evolution induced by oscillatory flow over bed ripples and wave propagation and breaking over perched beach configurations. The bed-ripple configurations include validation against experimental measurements and the effect of mixed-grain sediment on ripple dimensions. Bed load is based on empirical formulas and suspended load on an advection-diffusion equation for mixed-grain sand. Bed evolution is calculated using the Exner equation with a diffusion term. A parallel algorithm based on OpenMP will be implemented on Cartesian grids, using the immersed boundary (IB) method for the imposition of bed boundary conditions. The perched-beach configurations include the effect of varying sill heights, nourished sand sizes, and different incoming wave conditions (regular and irregular) using OpenFOAM. Validation will use experimental data on sediment transport, wave breaking and transmission over submerged bars.