An investigation on mechanisms of equilibrium-stage scour and deposition process around a submerged L-head groyne

Abstract

ABSTRACT A numerical model based on large eddy simulation code supported with a laboratory experiment was used to explore the mechanism of scour and deposition process around a submerged L-head groyne at equilibrium stage of flow. The numerical model used the equilibrium bathymetry, which was obtained from an experiment conducted in the laboratory. The components of Horse Shoe vortex system (HV) including the presence of aperiodic oscillatory motions between back flow and zero flow modes near the groyne faces junction are explored. Formations of elliptical-shaped vortex tubes along detached shear layer (DSL) and their merging phenomenon at different time scales of flow are also investigated. Increase in vorticity magnitude towards bottom as compared to upper planes for instantaneous and mean flow field is identified. Near bed region, concentration of DSL profile towards submerged mound situated in the wake region emerges as dominating factor over HV system for the production of larger vorticity magnitude. Transportation of DSL eddies, their interaction with wake vortices and flow within reattachment zone are also focussed. To emphasize, this innovative study was conducted first time to fulfil the gap of exploring mechanism of scour and deposition process around such a complex geometry under submerged condition over scoured bed.