Impacts of wave-induced seabed response on local scour around a pipeline: PORO–FSSI–SCOUR

Impacts of wave-induced seabed response on local scour around a pipeline: PORO–FSSI–SCOUR–FOAM

Zhai, Hualing / Jeng, Dong-Sheng

Abstract The problem of local scour around a submarine pipeline is vital for oil and gas projects. Conventional scour models around pipeline practically include the flow and sediment transport characteristics, but they ignore the interactions between flow and seabed soil in the scouring process. In this study, a new two-dimensional model for simulating the scouring process is established while considering the impact of the wave-induced soil response and the associated seepage. With the present model, the influence of seepage and soil response on the modified Shields number, repose angle and prediction of the local scour depth and profile are examined. The numerical results indicate that the influence of repose angle when modified by seepage in the whole scour process is small. Meanwhile, the wave-induced dynamic soil response promotes the development of the scour profile and eventually increases the maximum scour depth to some extent, regardless of the change in the soil characteristics. However, at smaller KC numbers, the variations in the maximum scour depth with seabed properties become more significant.

Graphical abstract Display Omitted

Highlights • A novel scour model considering soil response is numerically established in OpenFOAM. • The shape of the scour hole is asymmetrical due to the asymmetrical horizontal flow velocity. • The maximal scour depth with the soil response is larger than that without the soil response. • The difference in $S / D$ with and without soil response would decrease with increasing in the KC number. • The soil response should be considered for a smaller shear modulus, lower soil permeability, and lower saturation.