Estimation of Particle Concentrations Using the Stochastic Particle Tracking Method in Open Channel Flows

Proper estimation of sediment concentrations in open channel flows is of critical significance to establish a viable water resources management plan. When modeling suspended sediment, sediment concentrations can be estimated from either the Advection-Diffusion equation or the empirical relationship with flow discharge. Although these methods provide fairly reasonable estimates of concentrations, there have recently been several accounts that point to the probabilistic properties of sediment particle movement in open channel flows. This paper attempts to develop a stochastic approach for quantifying the sediment concentration in open channel flow. The effect of probabilistic flow characteristics on sediment concentrations will be evaluated and discussed. The probabilistic characteristics of flows include random occurrences of large flow perturbations as well as turbulence. We take the Lagrangian approach to examine the uncertainty associated with random properties of sediment movement. In particular, we include the stochastic flow velocity into governing equations of sediment transport. The proposed method will be verified against experimental data. The proposed approach is expected to characterize the probabilistic property of sediment concentrations in open channel flow.