Description

A discrete element model (DEM) is coupled to direct numerical simulation (DNS) of turbulent flow to provide a close-up view of how sediment at a river bed is mobilized and transported downstream. By tracking individual sediment grains in this idealized numerical simulation, statistical quantities, such as the mean displacement, the transport intermittency, and the probability distribution of jump times and lengths, are calculated and used in upscaling bulk transport. Advanced models designed to capture intermittent and anamolous behavior are developed so that transport rates near the threshold of sediment motion can be accurately predicted for use in large-scale models.

For more information:

• González, C., D.H. Richter, D. Bolster, S. Bateman, J. Calantoni, C. Escauriaza (2017), Characterization of bedload intermittency near the threshold of motion using a Lagrangian sediment transport model, Environmental Fluid Mechanics, 17, pp 111-137

Project Aims

1. Use numerical simulations to identify the onset of sediment transport
2. Quantify intermittency in sediment flux near the threshold of motion
3. Model bulk transport rates and develop upscaled models for transport