The numerical study of wave-induced pore water pressure response in highly permeable seabed

Abstract

The coupling numerical model of wave interaction with porous medium is used to study wave-induced pore water pressure in high permeability seabed. In the model, the wave field solver is based on the two dimensional Reynolds-averaged Navier-Stokes (RANS) equations with a k-ɛ closure, and Forchheimer equations are adopted for flow within the porous media. By introducing a Velocity-Pressure Correction equation for the wave flow and porous flow, a highly efficient coupling between the two flows is implemented. The numerical tests are conducted to study the effects of seabed thickness, porosity, particle size and intrinsic permeability coefficient on regular wave and solitary wave-induced pore water pressure response. The results indicate that, as compared with regular wave-induced, solitary wave-induced pore water pressure has larger values and stronger action on seabed with different parameters. The results also clearly show the flow characteristics of pore water flow within seabed and water wave flow on seabed. The maximum pore water flow velocities within seabed under solitary wave action are higher than those under regular wave action.