The Research Of The Four Degrees Of Freedom Maneuverability Of VLCC Under The Effect Of Wind

Along with the continuously increasing demand for crude oil, its transportation has become an important part of international economic trade. VLCC (Very Large Crude Oil Carrier), the main type of crude oil transportation, whose block coefficient and moment of inertia are both large, so its maneuverability is different from general ship and the deflection under the influence of the wind is abnormal. In the event of oil spill accident, it will bring great damage to the ocean environment. Hence, the research on VLCC maneuvering has become an important subject to ensure the marine traffic safety.By referring to the literature from both domestic and basing on the research of others, this paper adopts MMG(Maneuvering Model Group) thought to establish a maneuvering motion mathematical model for VLCC of four degrees which are more complete and comprehensive including rolling. Also, the paper utilizes MATLAB to simulate the maneuverability which is interfered by the wind and the flow, etc. In addition, the paper carries out deep and shallow water turning cycle simulation experiments. Finally, the paper makes a contrast with the real ship’s and verifies that the accuracy of the model is within the range of requirement.Based on the model established, the paper conducts the course-keeping simulation research of different load conditions under different wind direction, different wind speed and different ship speed, etc. Then its turning circle affected by different wind speed and different flow speed is simulated. Afterwards, the paper calculates leeway and drift angle at different ship speed, different wind speed and different current speed. The simulation results show that when VLCC is under headway in full load and even draft, its bow will turn to the windward whatever the wind direction is; when VLCC is in ballast condition, its bow will turn to the leeward if it is subjected to strong wind before the beam and the ship speed is slow, and its bow will turn to the windward if it is subjected to strong wind after the beam and the ship speed is high. This paper can make a better understanding of VLCC maneuverability for ship officers and provide guidance for practical ship handling.