The Prediction Of Ship Manoeuvrability In Initial Design Stage

With the development of shipbuilding and shipping, ships' displacement tends to bigger than before, and the speed is faster than before, and the number of ships in the old ditches or old channels increases, it is easy to see the main reason for shipping accidents is that the shipping density ascends. Therefore, it is urgent that we should improve the ship maneuverability immediately. Though people have taken a lot of measures, the accident of ship collision happens repeatedly. On the one hand, most accidents of the collision are caused by the navigator carelessness. On the other hand, if the ship has not good maneuverability, the accident would not be avoided. So, to reduce human error is very important for navigation safety.In order to solve the above problems, International Maritime Organization (IMO) attaches great importance to the role of training and evaluation of ship maneuverability for ensuring ship navigation safety. One of the most promising means is the ship handling simulator (SES), based on mathematical modeling of ship motion. SES is the validity which is used for wreck analysis and for ship designing. Thus, many countries have studied in indifferent areas about ship maneuverability (whether it is in deep and shallow water, unrestricted water or restricted water etc.)At the meantime, IMO and many countries have worked together to improve the ship maneuverability at difference areas for long time. In December 2002, IMO has issued the Resolution MSC.137 (76), Standard for Ship Maneuverability. For applying the standards, we have to estimate the ship maneuverability at the design stages as accurate as possible, then that could be shorten the cycle and reduce expenditure of shipbuilding, also be insure the ship could accord with the standard. So, it is main problem that set up mathematic model for ship motion simulation. However, the calculating definition of maneuverability motion depends on the hydrodynamic derivatives. For this reason, the purpose of this article is: apply newly hydrodynamic derivativesformula to calculate hydrodynamic forces and offer the ship maneuverability index during the design stages.During the processing system development, firstly, set forth the methods, importance and two recently formulas of hydrodynamic derivatives. Secondly, based on the MMG module the maneuvering motion equations are established for the ship in still and deep water. To compile and run the program, the calculation results compared with the experimental data. Then, to carry through turning test, zigzag test and stopping motion numerical simulation based on the Standard for Ship Maneuverability issued by IMO. At last, taking into consideration of wind in ship maneuverability motion simulation has been accomplished.