Seminar - Sally Williams - Modelling Interfacial Wave Attenuation
Wednesday 10 October 2007, 1.10 - 1.50 pm
Civil Engineering Lecture Theatre 3
Density variations are known to occur within the ocean due to changes in temperature, salinity and suspended particulate concentration. Such deviations from homogeneity can be manifested as a continuous variation or as step-like change. In this seminar we will investigate the propagation of two-dimensional progressive interfacial gravity waves on a two-layer step-like stratification of two different but constant densities, where the two fluid layers are considered to move above a permeable seabed. A nonlinear analytical solution assuming potential flow of miscible, inviscid and incompressible fluids is considered in addition to the numerical solution of the incompressible Navier-Stokes equations using an Arbitrary Lagrangian-Eulerian (ALE) finite element method. The effects of geometric and flow parameters such as ratios of depths and densities of the two fluids and seabed characteristics on the viscous attenuation of waves due to the combined effects of the wave interaction with the porous seabed, damping within the fluid layers, and damping at the interface of the two fluids will then be studied and discussed.