Three-dimensional simulations of offshore oil platform in square and diamond arrangements (Q2247623)

Summary: The interaction of the solitary wave with an oil platform composed of four vertical circular cylinders is investigated for two attack angle of the solitary wave \(\beta= 0^\circ\) (square arrangement) and \(\beta= 45^\circ\) (diamond arrangement). The solitary wave is generated using an internal source line as proposed by the second author et al. [``Internal inlet for wave generation and absorption treatment'', Coastal Eng. 56, No. 9, 951--959 (2009; \url{doi:10.1016/j.coastaleng.2009.05.001})]. This generation method is extended to three-dimensional wave flow and is integrated into the PHOENICS code. The volume of fluid approach is used to capture the free surface evolution. The present model is validated in the case of a solitary wave propagating on a flat bottom for \(H/h=0.25\) where \(H\) is the wave height and \(h\) is the water depth. Compared to the analytical solution, the pseudowavelength and the wave crest are well reproduced. For a solitary wave interacting with square and diamond cylinders, the simulated results show that the maximum run-ups are well reproduced. For the diamond arrangements, the diffraction process seems to not affect the maximum run-ups, which approached the isolated cylinder. For the square arrangement, the shielding effect leads to a maximum wave force more pronounced for the upstream cylinder array.