An investigation of the shoaling of large amplitude internal waves using computational fluid dynamics

The transformation of internal waves in shallow water is important for stuhes of energy dissipation and for enhanced mixing of nutrients and pollutants in the ocean. The wave transformations are also important because they affect the propagation of sound in the upper surface layers of the ocean and the flows induced by the waves may affect moored oil platforms and submersibles. In this paper attention is focussed on the behaviour of a typical large amplitude internal wave passing into shallow water. A Computational Fluid Dynamics (CFD) code is used to solve the full, two-dimensional time dependent conservation equations for the fluid. Turbulence is modelled using a two equation turbulence model with account taken of the effects of stratification on turbulence. The CFD simulations predict the wave transformations occurring as the primary wave propagates on-shelf and the velocity distributions, turbulence production and fluid transport induced by passage of the waves.