A CIP-based numerical simulation of freak wave impact on a floating body

The purpose of this work is to develop advanced numerical tools for modeling freak waves impact on a floating body undergoing large amplitude motions. An improved model governed by the Navier-Stokes equations with free surface boundary conditions is presented for nonlinear wave-body interactions, in which a more accurate Volume of Fluid (VOF)-type scheme, the Tangent of hyperbola for interface capturing/Slope weighting (THINC/SW) is adopted for interface capturing. The model is solved by a Constrained Interpolation Profile (CIP)-based high order finite-difference method on a fixed Cartesian grid system. A focusing wave theory is used for freak wave generation. Newly designed physical experiments in a two-dimensional glass-wall wave tank are performed for benchmark validation. Fairly good agreements are obtained from the qualitative and quantitative comparisons between numerical results and laboratory data regarding to distorted free surfaces and large amplitude body motions. Some discrepancies are found for the predicted peak pressure. The effects of grid resolution on body motions and impact pressure are performed for error analysis. The comparison of the numerical results and measured data reveals that the proposed model is capable of reproducing the nonlinear dynamics of the floating body for applications.