Simulation of Wave Induced Forces on Semi Submerged Horizontal Cylinders Using OpenFOAM®

Abstract

The work presented in this thesis documents the simulation of wave induced forces on semi submerged horizontal cylinders in OpenFOAM, utilizing the blending method for generation and damping of waves. The blending method is not included with OpenFOAM and thus required development before it could be employed. Both a linear Airy wave model and a fifth order stokes wave model are implemented. The blending method is implemented as an extension of the laminar multiphase solver interFoam, utilizing the volume of fluid method for capturing the interface and the finite volume method for spatial discretization. A validation study is carried out aiming to confirm that the simulated waves accurately represent reality. Simulation results are compared with experimental data, in this study the property compared are wave induced forces on a partially submerged cylinder. Time force histories for three different cylinder axis submergences and wave amplitudes are presented. The agreement between experimental forces and simulation forces is good. A verification study is attempted. This study shows significant deformation of the surface profile, most notably a raising of the trough and a lowering of the crest. The cause of the deformation is still unknown.