A method of computational fluid dynamics is investigated for numerical simulations of strongly nonlinear phenomena with the large deformation of the free surface. The numerical solution method of this study is based on the CIP (Constrained Interpolation Profile) scheme, and the multigrid technique for solving a pressure Poisson's equation with high efficiency and robustness. The method developed was applied to dam breaking and sloshing in a tank. As a result, the numerical computations confirmed that the method developed provides fairly efficient and robust computations in 3-dimensional simulations of violent free-surface flows involving strong water impacts.
From the perspective of seakeeping performance in rough seas, both global motions of a ship and local wave loads on structural materials should be concurrently clarified. Under the condition of high wave heights, several phenomena such as slamming, water on deck, water impact by green water, and violent sloshing in tanks continuously occur. Thus, theories or numerical methods of seakeeping problems should be able to predict the 2 points noted above with high efficiency and high robustness in order to use results obtained from numerical computations in practical ship design. The physical phenomena noted above involve large deformations of the free surface such as wave breaking and water spray. This means that these have strong nonlinearity. Thus, Computational Fluid Dynamics (CFD), which directly solves primitive forms of hydrodynamic equations, is useful for responding to the needs listed above. Recently, several newly developed schemes have been proposed that are capable of simulating fine structures of the free surface in a multiphase flow field (liquid, gas and solid). For example, Kleefsmann et al. (2004, 2005) simulated wave impact problems using the Comflo that is based on the finite difference method and VOF for capturing free surfaces.
