Application of 3D mobile bed, hydrodynamic model

The prediction of sediment erosion and deposition magnitudes has challenged many investigators. One- and two-dimensional sediment transport models are commonly used for predicting sediment scour and deposition. They are adequ ate for many engineering applications; however, for some problems, only a t hree-dimensional model should be used. A three-dimensional model is necessa ry for predicting sediment erosion and deposition whenever significant seco ndary currents exist, such as in river bends, crossings, distributaries, or diversions. In diversions, for example, the sediment load may not split in the same proportions as the flow. A three-dimensional model can be used to estimate the sediment split. This paper presents a description of the thre e-dimensional numerical model CH3D-SED and the governing equations for the model. The validation of the model and its application to the Deep Draft Na vigation Project on the lower Mississippi River also are presented.