EAPSI:Predicting Bed Elevation Change in Rivers Using Computer Simulation

Kim Hansang, College Station TX

Investigators

Abstract

Sediment transport is the movement of sediment particles, such as clay or sand, in a moving body of fluid. Predicting sediment transport in open channel flows has numerous implications in civil engineering and related fields, and it is of a great interest to engineers and other stakeholders, including government agencies. For instance, buildup of sediments in waterways poses great threat to vessels by reducing the under-keel clearance, the distance between the ship?s lowest point and the channel bed. With the advance of computing capabilities in the recent decades, simulation of sediment transport, even in very complex flows, has been made possible through Computational Fluid Dynamics (CFD). CFD is a technique by which a flow of water is simulated on a computer and the amount of sediments transported as well as the resulting bed elevation changes are predicted. Using CFD, the proposed project will investigate the sediment transport and bed elevation change in the Ara Waterway of Korea, an 11-mile long artificial canal that connects the Han River to the Yellow Sea, under different flow conditions. The collaborator is Dr. Van Thinh Nguyen, the director of Computational Fluid Dynamics Laboratory in Seoul National University, Korea. Lessons from this research can be applied to navigable waterways in the U.S. and elsewhere to aid in monitoring of channel beds for under-keel clearance and with waterway maintenance. For this project, the following two CFD models will be used: FANS3D and TELEMAC. FANS solves three-dimensional Reynolds-Averaged Navier-Stokes equations with the finite analytic scheme in non-staggered, general curvilinear coordinate systems. TELEMAC, on the other hand, solves the full Navier-Stokes equations and uses the finite element method as the discretization scheme. The two models? capabilities in simulating sediment transport have been validated for numerous flow environments, but this will be the first effort to compare and analyze their predictions. The findings will lead to reduction of efforts and costs associated with monitoring channel beds for under-keel clearance requirement and with waterway maintenance. This award is funded in collaboration with the National Research Foundation of Korea.