Seafloor pressure signatures of a high-speed boat in shallow water with SPH

Smoothed Particle Hydrodynamics (SPH) based simulations are implemented to evaluate the pressure-induced signatures on the ocean floor due to the passage of a high-speed boat in quiescent shallow water. Along with the standard Weakly- Compressible SPH (WCSPH) equations, the delta-SPH formulation is employed, which modifies the SPH continuity equation by incorporating numerical diffusion. This correction allows for a considerable reduction of the spurious oscillations characterizing pressure fields obtained with WCSPH algorithms. A simple computer model of a planing boat is developed for comparison with similar works in the literature. Simulations are performed using a parallel open-source SPH code on a high-end graphics processing unit (GPU). A convergence study on the size of the optimal computational domain is carried out, with a total number of particles per simulation ranging between 100,000 to 20,000,000. Part of the computational work is directed towards the investigation of the best set of SPH parameters to be employed in this specific study, with particular attention to the choice of a suitable kernel function, particle resolution and viscosity coefficients. Pressure contours and pressure plots at lateral locations at the seafloor are presented, showing good agreement with previous studies. It can be inferred that the SPH methodology is a suitable choice for free-surface problems, offering a good trade-off among the ease of implementation, computational efficiency and accuracy of the results.