Verification of a boundary element model for wave forces on structures with porous elements

Hydrodynamic parameters on structures with porous elements can be significantly altered compared to those on solid structures. The use of a porous support structure for a floating wind turbine could potentially reduce platform motions and wave forces, correspondingly reducing adverse effects on the wind turbine, such as fatigue damage and loss in energy capture. This paper presents a Boundary Element Method (BEM) to calculate linear wave forces on solid structures with a porous wall bounding an interior volume of water. In the model, the shape of the solid and porous elements of the structure can take arbitrary shapes and be either surface-piercing or fully submerged. Initial verification results are presented against existing commercial BEM software for solid bodies and analytical results for solid/porous structures with simple geometries. In all cases, the comparisons show good agreement, giving confidence that the method can be used in more complex cases where analytical results cannot be derived.