Large Eddy Simulation of a sediment particle under entrainment conditions

A Large Eddy Simulation of a fully developed turbulent open-channel flow with Reynolds number Re=71,755 was performed to study dynamics coherent structures in the vicinity stationary sediment particle. The particle positioned at bottom on smooth channel bed. impulse concept employed by computing three-dimensional hydrodynamic forces acting order predict onset motion. Results quadrant analyses high events yielded mostly outward and sweep events. Auto- cross-correlation field were studied discussed. An identification showed that large-scale, long-lived hairpin-like vortices whose bed-normal lengths are larger than ?100 viscous units resulting an increase lift drag simultaneously, facilitating initiation