Validation of a numerical code by a particle method for violent free-surface problems

In the field of naval and ocean engineering, the reasonable estimation of impulsive loads from fluid is an important piece of information for the safety of ships and marine structures. The large deformation of the free surface is one of the most difficult problems for numerical simulations of fluid motion. There are many kinds of numerical techniques with which to treat the problem. Most of them have tried to capture the free surface by the use of some scalar function such as a density function on the grid system. On the other hand, there is a different approach to the problem: Particle methods that use moving particles as a proxy for a grid or mesh system. The most popular particle method is the SPH (Smoothed Particle Hydrodynamics) method. A technique to apply it to incompressible flow was initiated by Monaghan (1994). In the field of marine hydrodynamics, there are some applications of the SPH method (Fontaine et al., 2000; Landrini et al., 2002; Souto and Pavon, 2003). Its capability to treat violent free-surface flow has been already shown. In this paper, the method is based not on the SPH method but on the MPS (Moving Particle Semi-implicit) method initiated by Koshizuka in the field of nuclear engineering in order to simulate violent motions of a boundary (1996). There is the preceding research of the MPS method by Goto et al. (2001). This method is quite different from the SPH method regarding the spatial discretization and velocity-pressure computing scheme.