A Smooth Particle Hydrodynamics discretization for the modelling of free surface flows and rigid body dynamics

Abstract

Summary This work describes a unified discretization of rigid solids and fluids, allowing for spatially detailed and time‐resolved simulations of fluid–solid interaction. The model is based on a Smoothed Particle Hydrodynamics (SPH) discretization of the Navier–Stokes equations and Newton's equations for rigid body dynamics. A δ ‐SPH term is added to the continuity equation, allowing for an effective interface description. The benchmark case of the buoyancy‐driven motion of an unrestricted rigid body allows for experimenting new computational approaches for the more general case of fluid–solid interactions, in the case of solid objects larger than the smallest flow scales. Numerical experiments and analytical solutions are recovered from the literature and compared with the numerical results from the proposed model. Experimental measurements were performed and numerical results are compared, resulting in a wide range study of the fundamental properties of fluid–solid systems. After an investigation on the influence of the stabilizing δ ‐SPH terms, the model is shown to respect free stream consistency, the correct dynamics of a buoyant body, for a range of positive and negative relative densities and the correct recovery of equilibrium states. This work addresses these topics in an attempt to characterise the presented model with regard to the quality of its solutions and possible limitations. Copyright © 2015 John Wiley & Sons, Ltd.