Collaborative Research: Computational Methods for Coupled Wave, Current, Sediment Transport and Morphological Evolution

Ohio State University Research Foundation -Do Not Use, Columbus OH

Investigators

Abstract

The goal of this project is to significantly advance the capability to accurately predict sediment transport and seabed morphology in three-dimensional coastal and estuarine environments. To achieve this goal, state-of-the-art algorithms for fully coupled wave, current, sediment transport and bed morphology will be developed, analyzed, and implemented. The development of this system will require a better mathematical and physical understanding of the tightly coupled nature of the various processes involved. In addition, it will require computational strategies which address the accurate and efficient coupling of interdependent processes that exhibit a wide range of spatial and temporal scales?both within the fluid motion itself and between the fluid and bed motion. Robust and highly parallelizable algorithms for the various processes will be developed based on discontinuous Galerkin finite element methods, and the coupling of these algorithms will be carefully investigated in order to maintain numerical accuracy, efficiency, and local mass conservation of sediment and fluid phases. Studying and predicting the morphodynamics of the coastal zone requires a detailed knowledge of winds, waves, currents, sediment transport and, ultimately, the resulting morphological changes of the seabed that occur as a result of these processes. The erosion and deposition of bed sediment can have a major detrimental impact on the coastal population, infrastructure and environment. For example, during Hurricane Katrina, four major levee breeches that occurred during the storm were a result of foundation-induced failures caused by scour. The transport of sediment is closely tied to a number of other issues in the coastal zone, including water quality and related ecological concerns, beach and shoreline erosion, and the maintenance of navigation channels and harbors through dredging activities. Accurate estimates of expected sediment transport and bed morphological changes can aid greatly in the long-range planning and management of coastal and estuarine environments. In this project, the investigators will develop a fully coupled wave, current, sediment transport and bed morphology model system. Such a system will significantly advance the capability to accurately predict sediment transport and seabed morphology in coastal and estuarine environments. From this research, a better scientific understanding of the complex interrelations among hydrodynamic, transport and morphodynamic processes in the coastal zone will emerge, which can lead to more informed decision-making that will help protect the coastal population and infrastructure. The developed software of the project will also provide a computational infrastructure that can be used in many other applications within the area of computational modeling. Furthermore, the technology developed under this project will be disseminated to government agencies such as NOAA and the US Army Corps of Engineers.