Hydrodynamic characteristics and motion response analysis of 40 000 DWT bulk carrier

The wave loads have a crucial impact on the maneuverability and safety in navigation. In this study, a 40,000DWT bulk carrier model was established, and the hydrodynamic software AQWA was used to simulate the hydrodynamic characteristics and motion responses of the ship under wave loads, combining potential flow theory and the theory of wave radiation/diffraction. On this basis, the combined effects of wind, wave and current loads are further considered, and the time-domain dynamic response of the ship under different sea conditions is calculated. At the same time, the time domain motion response of RAO corresponding to the angular degree of freedom of wave direction is also obtained. The variations of the six degrees of freedom of the ship's motion responses, as well as the F-K forces and diffraction forces with wave frequency, were obtained for different wave directions. The results showed that under low-frequency wave loads, the ship was susceptible to significant motion responses, regardless of whether it was under heading or transverse wave loads. There were differences in the six degrees of freedom motion responses between heading and transverse wave loads. The peak value of the F-K force corresponding to the wave direction was greater than that of the radiation force, and the F-K force had a greater impact on the structural motion response in all degrees of freedom. With the deepening of the harsh sea conditions, the time-domain motion response of the ship increases sharply, causing serious safety hazards to the ship.