The study focuses on the Lagrangian particle tracking of suspended sediment particles whose motions are strongly coupled with surrounding turbulent flows. The diffusion of suspended particles is often linked to turbulence diffusion theories. The high irregularity and protean properties of turbulence generally lead to the usage of Brownian diffusion. It implies that the spreading of suspended sediment particles is normally distributed and embeds independent properties in particle motions. However, the non-Gaussian phenomenon in sediment movements has been observed and recognized during the last decades. The sediment-laden flow experiments have suggested that coherent structures in turbulent shear flow strongly impact particles' suspension near the boundary. This study proposes an advanced Lagrangian particle tracking model, whose driven fluctuation process is the fractional Brownian motion (FBM). By introducing the fractional stochastic process to the PTM, the correlated increments aim to describe anomalous suspended sediment particles' movements resulting from intermittent and time-persistent coherent turbulent structures near the boundary. The proposed model is applied to simulate suspended sediment transport in two-dimensional open channel flow. Via Monte Carlo simulation, the ensemble statistics results are presented, including mean, variance, skewness of particle positions, and particle velocity fluctuations. The anisotropic sediment behaviors can be found in the probability density function (PDF) of particle velocity fluctuations at different water depths. Simulation results show improvements in the streamwise particle velocity profiles and in predicting sediment concentrations near the boundary.
