Three-Dimensional Simulations of Offshore Oil Platform in Square and Diamond Arrangements

Saliha Nouri,Aldo Munoz Vazquez,Ali Allahem,Salem Alkhalaf,Salah Mahmoud Boulaaras,Zouhair Hafsia,F Rabiei

doi:10.1155/2021/5578391

Abstract

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 β = 0 ° (square arrangement) and β = 45 ° (diamond arrangement). The solitary wave is generated using an internal source line as proposed by Hafsia et al. (2009). 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.

Highlights

In the last decades, many researchers have focused on searching different wave structures of nonlinear partial differential equations
The main task of the present study is to investigate the interaction of the solitary wave with one or four circular cylinders in a square or diamond arrangement using a (3-D) numerical wave tank (NWT)
For the diamond platform arrangement, the maximum wave run-ups approach to that on the isolated cylinder indicating that the diffraction process does not affect the four cylinders

Summary

Introduction

Many researchers have focused on searching different wave structures of nonlinear partial differential equations. The available analytical solutions in the literature are only valuable under some limiting assumptions For this reason, experimental and numerical methods are adopted to solve this wave-platform interaction problem. Wang et al (2021) in [8] investigate experimentally, the back and front run-up and wave forces induced by solitary wave for different truncated vertical cylinders. Mohapatra et al (2020) in [10] studied the regular wave diffraction by a floating fixed vertical cylinder by two methods: using a CFD code and analytically based on a Boussinesq model. Frantzis et al (2020) in [15] adopted a (3-D) numerical wave tank (NWT) to study the wave breaking induced by a single row of vertical cylinders for different ranges of cylinder diameter to depth ratios. The cut-cell implemented in the PHOENICS code is used to reproduce the circular cylinder shape

Mathematical Formulation

Numerical Results

Conclusions