In this paper, a computing method for water impact of arbitrary shaped bodies will be proposed. We use body-fitted coordinate system to model the arbitrary profile of the rigid body surface and the transient deformation of the free surface is solved by the fractional volume of fluid method. With this combination of the numerical techniques the rigid surface and the free surface boundary conditions are naturally treated at the intersection of both surfaces that improves remarkably the stability and accuracy of the numerical simulation.
For the purpose of verifying the present computing method, classical problems of water impact of wedges and circular cylinders are studied. Moreover, water impact of a ship bow section is simulated to illustrate the applicability of the present computing method to practical ship design problems. In these basic studies, we considered the cases in which the body enters an initially calm water surface with a constant velocity. The results of the simulations are examined against the existing analytical theories and published experimental data.