3-D Computation of Ship-Wave Interaction by CIP/Cartesian Grid Method

摘要

The current research is a step towards developing a CFD method to predict hydrodynamic loads for strongly nonlinear ship-wave interactions. Our challenge is to incorporate the local slamming and green water impact predictions in the global ship motion calculations. The motivation is that such local loads can be sensitive to the inflow conditions, which need to be determined from the calculation of ship-wave interactions. For several years researches have been done to develop a 3-D CFD code that can be both robust and efficient to compute complicated interactions of a freely moving ship with ambient free surface flow. Our numerical model is a Cartesian grid approach coupled with an interface capturing method. The CIP (Constrained Interpolation Profile) algorithm1 is adopted as the base scheme. As the underlying Cartesian grid does not depend on the body boundary and the free surface, the computation of a strongly nonlinear problem, which may require treatment of both complicated free surface deformation and violent body motion, can be more efficient and robust than conventional body fitted approach. The accuracy of the CIP based method for 2-D problems such as dam breaking, forced oscillation of a floating body, sloshing in tanks, water entry, have been validated. 3-D code development and its applications are ongoing. A lot of efforts have been done by the authors to make the method be not only able to handle complicated flow phenomena but also relatively simple in scheme which can perform three-dimensional simulations in an acceptable spatial and temporal resolution at reasonable cost. In this extended abstract we will describe some new improvements on 3-D code development and an application example of 3-D NWT for demonstrating the capability of the proposed numerical model.