Motion Prediction of Ships and Yachts by Smoothed Particle Hydrodynamics

Abstract

Smoothed Particle Hydrodynamics (SPH) is a (relatively) recent numerical analysis technique that facilitates the development of a virtual towing tank for the analysis of ship and yacht motions. SPH is a mesh-free interpolation method in which particles follow the motion of the material and its interfaces. Although the accuracy of the method merits further work, the SPH method when used to model fluid flow suffers neither from the inaccuracies of the Eulerian finite difference solution, nor from the large deformation limitations of Lagrangian finite elements. When water is analysed using mesh-free techniques, the simulation can model many non-linear phenomena including breaking waves as well as dispersion in splash-like events. The combination in the one analysis package of both mesh-based and mesh-free capabilities makes feasible the analysis of ship and yacht behaviour in waves. This physics-based analysis technique yields an approach that is unrestricted in its ability to model conventional displacement vessels, multi-hulled wave-piercing vessels, planing vessels or even submarines. Furthermore, airborne events such as those leading to slamming of yachts can also be analysed. This paper will present a number of recent case studies to demonstrate the flexibility of the SPH numerical towing tank for the analysis of ships and yachts in waves.