Numerical simulation of flow around a submarine pipe with a spoiler and current-induced scour beneath the pipe

A numerical study is performed on the flow field around a submarine pipe equipped with a spoiler in a rectangular configuration and the variation of seabed surface caused by current-induced scouring beneath the pipe. The study is aimed to investigate the effects of spoiler height and gap between pipe and seabed on flow characteristics and seabed scouring. Euler-Euler two-phase flow model is employed to capture the flow characteristics of seawater and seabed sandy particles based on two-dimensional Reynolds-Averaged Navier-Stokes (RANS) equations. And shear stress transport (SST) k-ω turbulence model is applied to model the turbulence. Simulations are carried out for relative spoiler heights of S/D = 0, 0.15, 0.25 and 0.35 and gap ratios (G/D) ranging from 0.2 to 0.5 with an interval of 0.1. The Reynolds number ranges from 0 to 5.076 × 104 in the computational domain according to the logarithmic velocity profile used in simulations. The numerical results show that both flow field around submarine pipe and seabed scouring are sensitive to the relative spoiler height and gap ratio. Increasing the spoiler height or decreasing the gap ratio can accelerate the self-burial process for submarine pipe equipped with a spoiler.