Experimental and numerical analysis of wave forces on a vertical truncated cylinder with different depths of submergence under focused waves

Abstract

Accurately determining the extreme wave forces acting on marine structures is crucial for ensuring their safety. This study investigates the maximum values and transfer functions of wave forces on a fixed vertical truncated cylinder under focused waves through experimental analysis and numerical simulations. Firstly, an experiment was conducted to examine the influence of the wave steepness kpAp, structural scale D/Lp and depth of submergence S2/d on both the horizontal and the vertical forces exerted on the cylinder. These factors were found to significantly influence the maximum values and transfer functions of the wave forces, particularly those of the vertical force during wave slamming events. To further understand the interactions between the focused waves and the vertical truncated cylinder, a numerical model based on the Reynolds-Averaged Navier-Stokes (RANS) equations in OpenFOAM was employed considering different heights above the surface of static water S1/d and varying depths of submergence S2/d. The validity of this model was confirmed by comparing its results with those of the experiment. Following this, the effects of S1/d and S2/d on the maximum values as well as the transfer functions of wave forces on the cylinder were discussed, including in scenarios involving wave slamming and wave overtopping events. Finally, an empirical formula for calculating the wave force was proposed, taking into account the influence of kpAp, S1/d, and S2/d on the inertial coefficient CM and the coefficient of pressure correction CP. The results demonstrated that this formula can be used to accurately predict the maximum wave forces exerted on the cylinder.