Flow-Sediment Interaction and Formation Mechanism of Sediment Longitudinal Streaky Structures in Rough Channel Flows

AbstractBed-load streaky structures are typical bed morphological features, yet its formation mechanism remains unclear. To fill this knowledge gap, flume experiments were conducted to quantitatively identify the characteristics of turbulent coherent structures, sediment particle movement, and bed surface structure. An innovative workflow was established that combines the particle tracking velocimetry method with the Kalman filter algorithm, specifically for identifying the trajectories of sediment particles on the bed surface. Feature matching velocity was applied to acquire the flow surface field and structure-from-motion (SFM) was used to reconstruct the three-dimensional bed topography. All the flow velocity, sediment movement, and bedforms show streaky features in the streamwise direction at 0. 068