Numerical Investigation of Ship Waves and associated Hydrodynamics over a Sloping Bed with a Non-hydrostatic Model

Abstract

The ship waves and related hydrodynamics over a sloping bed are investigated numerically in this paper, and we aim to clarify the characteristics of ship wave deformation and its hydrodynamic effects. Laboratory experiments are performed with a self-propelled ship model to produce various wave conditions over a sloping bed in the water flume, providing the datasets for validation works of numerical simulations. With the implementation of model sensitivity analysis, numerical calculations of ship-induced waves and flow velocities are completed using the non-hydrostatic model in XBeach, and compared against experimental measurements. The results show that the model is not only able to calculate primary and secondary waves well, but also the ship-induced near-bed velocity, when ship waves are prominent in the water flume. Further numerical investigations of ship wave transformation and associated hydrodynamic effects are conducted over a sloping bed under different ship speed conditions. The ship wave height and run-up variations along the cross-shore transect clearly indicate the wave energy dissipation due to breaking and bottom friction. The ship-induced flow velocities are found to be mainly contributed by the low-frequency primary waves in our numerical experiments.