Ripple Morphology under Oscillatory Flow

摘要

Our ultimate long-term goal is to further the understanding of bed morphology and sediment dynamics under oscillatory flows. Experiments will be conducted to expand existing data sets of sand bed morphology and evolution in large scale laboratory facilities under controlled flow conditions. Based on this additional insight from the improved data set we aim to advance presently available tools for the prediction of sediment bed configuration. OBJECTIVES The main objective of this effort is to study the evolution and resulting final configuration of a uniform sand bed under various regular oscillatory flow forcings. In particular we would like to develop a robust dimensionless parametrization based on hydro- and sediment dynamics over the evolving ripple bed that gives understanding of the underyling physics controlling the occurrence of two or three dimensional ripples as well as the development of various ripple types (e.g., orbital, suborbital, anorbital ripples, round crested ripples, etc). Furthermore, through this parametrization, we aim to establish better ripple predictors that can better determine the sand bed morphology for specified hydrodynamic conditions.