A QSFDI based Laplacian discretisation for modelling wave-structure interaction using ISPH

The incompressible Smoothed Particle Hydrodynamics (ISPH) is one of the most popular Lagrangian particle methods for modelling wave-structure interactions. It solves unsteady Navier-Stokes and continuity equations using projection method, in which solving pressure Poisson's equation (PPE) plays a critical role. To discretise Laplacian operator, quadric semi-analytical finite difference interpolation scheme (QSFDI) has been developed recently relevant patch test demonstrated its superiority over existing schemes at similar accuracy level terms convergence robustness. In this paper, QSFDI adopted by ISPH discretising operator PPE. (ISPH_QSFDI) then applied to various cases with wave propagations impacts on structures. For purpose comparison, other discretisation schemes, including classic widely ISPH, CSPM CSPH2Γ, have also considered. Except discretisation, numerical implementations are kept same as ISPH. convergence, robustness these analysed reference either analytical solutions or experimental data. results demonstrate that present ISPH_QSFDI leads more accurate number particles costs less computational time achieve specific accuracy, compared although rate seems be one-order lower than theoretical primarily due fact linear used right-hand side PPE, gradient/divergence estimation treatment boundary conditions.