The present study is to investigate numerically the impact pressure on structures above sea level due to solitary wave slamming by using the volume of fluid (VOF) method. Appropriate moving contact-line boundary conditions are introduced to model wave impact on and separations from the structure. The predicted impact pressure magnitude are compared with available experimental data. The computations have been carried out at a range of heights of structure bottoms above sea level/water depth (s/d) from zero to 0.4, with a wave height/water depth ratio (H/d) from 0.24 to 0.45. The impact pressures and forces on structures, wave heights in front of structures and velocity fields are obtained.
The horizontal members of coastal and offshore structures such as a pier or an offshore drilling platform may be subjected to significant impact pressures due to wave slamming. It is characterized by an initial peak pressure of considerable magnitude but of short duration, followed by a secondary pressure of less magnitude but of longer duration. In addition, the buoyancy force acting on the member now varies with time. The many problems related to wave slamming, such as the compressibility of air between the structure and water surface, entrapped air in the water, wave breaking and turbulence, have not been studied extensively. Wave slamming on slender structure members has been addressed in several publications. Based on incompressible potential flow theory, Kaplan and Silbert (1976) developed a solution for the forces acting on a horizontal cylinder from the instant of impact to full immersion by a wave system that propagated normal to it. It is assumed the wave lengths are large compared to the cylinder radius so that the wave elevation is locally flat in its intersection with the cylinder. Another approach is to model the wave slamming by the formula similar to the Morison equation.