Unified viscous and potential prediction method for the coupled motion of damaged ship and floodwater in calm water

摘要

The coupled interaction between the damaged ship motion and flooding water is very complicated, and the time-domain coupling should be considered for the accurate prediction of ship stability. In this paper, we propose a nonlinear time domain unified viscous and potential prediction method for the prediction of ship dynamics coupled with floodwater. In this method, the nonlinear three-dimensional time domain hybrid source method is used for the simulation of ship motion and the fully viscous method is used for the simulation of the motion of floodwater, which can take the advantage of potential theory in calculating ship motion and viscous theory in calculating floodwater. Firstly, the theory basis, mathematical model and calculation process for this unified method are given. Secondly, two boundary conditions and two time scales for the match between potential theory and viscous theory are proposed. Thirdly, taking the ITTC benchmark model as an example, the simulation results in calm water by this unified method with different boundary conditions are compared with fully viscous simulation results and experimental results. The research show that the proposed unified prediction method can predict the dynamics of ship motion and describe the details of flooding water very well, at the same time, the calculation time can be saved a lot compared with full viscous method as the grid number for viscous simulation is considerably reduced.