CFD-FE Simulation of Wave Slamming on an Offshore Platform in Extreme Sea States

Abstract

Fluid flow and structural deformation of a floating platform during extreme wave slamming events are simulated by Computational Fluid Dynamics (CFD) and Finite Element Method (FEM) in coupled ways, in both model and full scale. The objective of the simulations is to verify correlation between slamming impact pressure on scaled platform model in the wave basin set up and full-scale platform in the real sea when the rigidity of the hull surface is considered. The slamming load and structural response simulated by CFD-FE analysis is first validated against analytic solutions and model tests for the following two cases:Wave slamming on rigid wall by breaking wave and water hammerDrop test of rigid and elastic structure on calm water The validated CFD-FE simulation set up is then applied to simulate wave slamming on three different realizations of a Spar hull structure:Rigid hull at model scaleRigid hull at full scalePressure panel at model scale In the CFD-FE modeling of the wave slamming at full- and model scale, compressibility of water/air and elasticity of the hull are properly modeled to simulate the difference between the hydroelastic effects at model- and full-scale set up. It has been found that the hydroelastic effect is minimal on full-scale Spar structure but can be significant on pressure panels at model scale. Further CFD investigations on other physical parameters that might affect the difference between wave slaming load at full- and model scale, such as surface tension, air entrapment and air-water mixture properties are made.