ABSTRACT
A numerical model has been developed to simulate local scour caused by a bed-mounted obstacle. The hydrodynamic module is based on the open source CFD software package OpenFOAM R and solves the Reynolds Averaged Navier-Stokes equations with a k-” turbulence closure model. The free surface is tracked using the Volume of Fluid scheme. The morphological module which has been developed consists of three components: a sediment transport module including suspended load and bed load, the Exner equation to measure the bed deformation level, and an avalanching mechanism which restricts the bed slope to be smaller than the angle of repose. The morphological change is then incorporated into the hydrodynamic field through automatic mesh deformation. The suspended load transport was validated independently using the theoretical sediment concentration distribution profile proposed by Van Rijn (1986). Then the model was used to simulate the scour caused by a submerged jet and the numerical simulation results have been compared with the experimental results. The computed velocity field agrees with the measured velocities, and the temporal evolution of the bed profile agrees satisfactorily with the experimental data
