Numerical study on the interaction between waves and twin pipelines in sandy seabed

Abstract

In offshore engineering practice, the construction of an identical cylinder close to the existing pipeline may largely affect the near flow field and hydrodynamic forces on the pipelines. The interaction between incident ocean wave and twin pipelines in sandy seabed plays an important role in the design of submarine pipelines. A mathematical model based on the Volume-Averaged Reynolds-Averaged Navier-Stokes (VARANS) equations, a two-equation k-e turbulence closure and an internal source term wave maker is adopted to describe this complex phenomenon. The sandy bed where the pipelines are partly buried is treated as a rigid porous material, and its impact on wave-pipeline interaction is considered in the VARANS model in terms of porosity and equivalent mean diameter of porous material. The impacts of burial depth and distance between the centers of twin pipelines on the wave-seabed-twin pipelines interaction are numerically investigated. The research results from numerical simulations indicate that the burial depth and relative position of twin pipelines significantly affect the wave-averaged flow velocity and dynamic pressure distribution.