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

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-ε
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 wavepipeline 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 waveseabed-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.