Nonlinear water wave interactions with floating bodies using the delta-plus-SPH model

Due to its robustness in modeling free surface flows and violent fluid-structure interactions, SPH method has been widely applied for simulating hydrodynamic problems in differentengineering fields. Among the different successful SPH variants, ?-SPH is an enhanced weakly-compressible SPH model widely used in recent years thanks to its benefits to the standard SPH scheme, to its low CPU costs and to its ease of implementation. Recently, an enhanced scheme named as ? + -SPH has been developed at CNR-INSEAN. In the new model, adaptive particle resolution is also implemented. That means in some local regions, the coarse particle can be refined and de-refined. The particle-shifting procedure is introduced and generalized in the context of multi-resolutions in order to prevent numerical instabilities. Wave-body interaction modeled with SPH method in multi-particle resolutions is rarelydocumented. In this work, ? + -SPH scheme is adopted to build a numerical wave tank (NWT) which can be utilized to simulate violent wave-body interactions. In the NWT, a piston wave maker is adopted to generate a focusing wave. A damping zone with high viscous coefficient is adopted to prevent wave reflection. Floating bodies with arbitrary shapes moving under the wave excitation in any amplitude can be simulated. Green water overtopping can be modeled.