Wave force on protected submarine pipelines over porous and impermeable beds using SPH numerical model

Abstract

A numerical model based on WCSPH method is utilized to simulate wave propagation over a pipeline. A hybrid approach is introduced to absorb outgoing waves based on gradual decrease of fluid velocity in an absorbing layer and using sloping beds simultaneously. The interaction of both regular and irregular waves with pipelines located on porous and impermeable sea-beds has been studied. The effect of pipeline distance to sea-bed on flow pattern and on the applied force is investigated for different geometries of pipeline protection by porous media and side slopes. Irregular wave spectra are studied and the model has been verified in comparison with other numerical and experimental data. The developed model simulates accurately the interaction of waves and a pipeline placed on a porous or an impermeable sea-bed, showing that forces on pipelines on permeable sea-beds are completely different than on impermeable sea-beds.