On the Stability and Wave Profile of a Ship in Oblique Waves

In the paper, the analyses of the stability and resultant wave profile for a ship advancing in oblique waves are made. A time simulation technique based on the previously well developed strip theory is used to calculate the ship motion and the relative wave elevation along the ship. An Instant Grid-Generation (IGG) technique is also applied to reduce the laborious work for the input preparation. The resultant wave elevation includes not only the incident wave but also the diffraction and radiation waves. To analyze the ship stability in waves, the instantaneous wave profile along the ship is derived. The wave profile prediction is also improved by using a more accurate estimation between the incident wave and hull side. The related hydrodynamic coefficients are treated in the manner of large ship motion, hence it is a nonlinear problem. From the present analysis, it is found that the ship stability in waves indeed differs from that in calm water. The authors regard that the present technique can offer more general ship stability analysis and will be helpful to understand the ship capsizing behavior in waves.