Abstract The weakly compressible and strictly incompressible formulations of the Smoothed Particle Hydrodynamics (SPH) method have been used to simulate the generation of solitary waves and the subsequent impact on a fixed vertical wall. Two wave generation methods, namely Scott Russell's wave generator and piston-type wave maker, have been compared. The aim is to verify and validate the SPH models for reproducing the desired waveforms and pressure profiles. The predicted run-up height and hydrodynamic load are compared with analytical solutions. The study concludes that both SPH models are able to reproduce the desired wave profiles satisfactorily. There exist some slight discrepancies in the water height at the upward and downward slopes immediately away from the crest for the incompressible SPH model. The subsequent maximum run-up height on a vertical boundary agrees well with the published experimental and numerical data. The incompressible SPH model has demonstrated a good consistency in reproducing stable and accurate pressure field for both wave generation methods considered. Large pressure fluctuations have been observed in the weakly-compressible SPH results, especially for the Scott Russell's wave generator case. As a result, the incompressible SPH model is capable of reproducing the instantaneous wall force that agrees well with published numerical force profile. The weakly-compressible model tends to significantly over-estimate the force on the solid wall after the maximum run-up height at large wave amplitudes. This research offers insights into the best practice of establishing numerical wave tanks, and is a prelude to the more challenging applications of the SPH method.

Abstract In this paper, a two-phase flow model is presented for simulating breaking wave impact on a rigid wall. The model is based on the Reynolds-averaged Navier-Stokes equations with the k-? turbulence model and developed under the framework of the open source CFD library - OpenFOAM. The governing equations are discretized by using the finite volume method and the air-water interface is captured by employing the volume of fluids (VOF) technique. With suitable predefined initial condition, three different types of wave impact on a vertical wall have been generated successfully. Following that, the pressure distribution and velocity field for air pocket impact are analyzed.

ABSTRACT: The characteristics of drag and lift forces on a circular cylinder model near a wavy boundary have been experimentally investigated in a water tunnel. In the range of the Reynolds numbers, based on the diameter of cylinder model, from 10 4 to 1.9 X 10 4 , the drag, lift force on the cylinder and lift force frequencies have been measured at the wave crest and trough and various distances from the wavy boundary. Flow visualization experiments revealed the wake structure varying as gap-to-diameter ratios (G / D) and mechanism Interacting between the cylinder and the boundary. INTRODUCTION In the offshore engineering, pipelines are used to convey oil and gas for power generation, sea-water for desalination, sewage for disposal at sea, and for the protection of communication cables. There are numerous problems associated with the design and installation of pipeline in deep-water offshore. The submerged pipelines are often fixed by concrete saddles and buried by dredging and trenching the sand at a seabed. It has been known from the practice that pipeline spans can occur due to local scour of the bed sediment The proximity of a pipeline near a seabed boundary gives rise to hydrodynamic and environmental problems m offshore engineering. Research on flow field and forces on the cylinder at various distances from the seabed boundary are of a great interest to many. There are many investigations (see Davis,1976) on forces on submerged pipelines In flow or wave. A lot of research works also have been carried out about wave forces on a cylinder near a plane boundary (see Sarpkaya,1981, Shankar et al.,1988). However, researches of hydrodynamic forces on a cylinder near a plane boundary in steady flows are relatively scarce. Second, the plane boundary changes the symmetry of flow about the cylinder nearby.