Accurate prediction of hydrodynamic loads on offshore structures is of great importance for the safety design of offshore platforms in severe environment. In this work, the generation of breaking focusing wave is carried out and the wave loads on a truncated circular cylinder is investigated using the in-house CFD solver naoe-FOAM-SJTU. The time history of wave elevation at focusing location is compared with experimental data provided by KRISO. The numerical forces, pressures and the scattered wave surface elevations around the cylinder are presented. The results show that the present CFD solver can be an effective tool to deal with breaking wave-structure interactions.
Wave breaking is one of the most common sea conditions and plays an important role in many engineering problems. The forces from breaking waves have been a major concern in coastal and offshore engineering. Evaluation of breaking wave impact on fixed or floating structures is of great significance. Theoretical approaches for studying breaking wave forces are generally based on the Morison formula (Morison et al., 1950). Due to the high impact forces during a breaking wave process, an impact force term must be added to Morison formula to describe the total force from breaking waves. However, theoretical approaches are still inadequate in evaluating wave breaking force. So numerous researchers have done experimental and numerical studies on breaking wave forces on cylinders.
Previous investigations of wave forces on cylinders were mainly carried out by model tests performed in a marine basin. Wienke and Oumeraci (2005) examined the plunging breaking waves acting on a slender cylindrical pile. The time history and the intensity of slamming force were analyzed. They found that the impact force was strongly depended on the distance between breaking location and cylinder. Zang et al. (2010) carried out physical experiments on the interaction of breaking and nonbreaking steep waves with a fixed vertical cylinder. The free surface deformation around the cylinder and the horizontal forces for different wave conditions were investigated. Arntsen et al. (2011) conducted small scale experimental tests and presented the results of plunging breaking wave impact forces on a single fixed vertical cylinder. They found that the slamming force intensity along a vertical pile is triangularly distributed. Mo et al. (2013) performed laboratory experiments for solitary waves breaking on a constant slope and investigated the impact of a shoaling solitary wave on a vertical cylinder. Kim and Kim (2001) used the diffraction and the Morison method with a universal nonlinear input output model to simulate the impact forces and wave kinematics of a Draupner freak wave on a vertical cylinder.
