Mathematical Modeling of Suspended Sediment in Nonuniform Flows

Abstract

A two‐dimensional vertical mathematical model for suspended sediment is presented. The model is based on the width‐integrated convectiondiffusion equation for the sediment particles including settling effects. The local fluid velocities and mixing coefficients are described by a new so‐called Profile model, which is based on the application of flexible profiles to represent the vertical distribution of the basic variables. Measured and computed velocities of strongly nonuniform flows were used for calibration of the Profile model. A stochastic approach is introduced to represent the sediment input at the bed. A bed concentration or an upward sediment flux can be specified (optional). The convection‐diffusion equation is solved by a finite‐element method, which proved to be better than a finite‐difference method. An extensive sensitivity analysis is presented to show the influence of the main controlling parameters of the model. Finally, a verification analysis is presented using flume and field data of dredged trenches.