Research On Simulation For The Maneuvering Of Abnormal Ship Model

With the rapid development of shipping industry in China, the technology of ship model has become increasingly important in the navigation channel regulation and ship navigation. Ship model experiment than the traditional theoretical calculation is more intuitive and reliability, so it is widely applied to practical engineering. Nowadays, the normal ship model technology is most widely used in China, after years of research and practice, normal ship model technology is already quite mature. But in reality, due to the experimental conditions and funding, many hydraulic models are abnormal models, how to apply ship model technology to the abnormal hydraulic models is still a challenge. Due to the geometry of the abnormal ship model is different with real ship,so it is difficult to ensure a similar motion and power with real ship. At present,abnormal ship has few studies in China and foreign,just do some similar studies in ship shape and ship movement,although there have been abnormal ship modeling techniques be applied to the actual project,but they did not do in-depth research and their works is very rough.If we can study in depth to abnormal ship model from the facts of ship maneuvering,not only can greatly enhance the practical value of ship model technology,but also can greatly reduce the investment funds from the construction funds of normal hydraulic model which in order to do ship model experiment.This paper have deduced the size ratio of abnormal ship model maneuvering facts based on the basic theory of abnormal hydraulic model,at the same time do a simple analysis the change of abnormal ship model maneuvering based on first order ship maneuvering response equation.The main work of this paper is based on the ship maneuverability equation of MMG,get mathematical model of abnormal ship model maneuvering.Have simulated Z-test and the rotation test of fore different variable rate abnormal ship model using MATLAB,get the factors and the impact of abnormal ship model model experiment.According to the simulation calculations and found that the rate of change is small when the metamorphosis ship model η= 1.1, because the force have small change in the ship model,rudder,propeller when ship is moving,its Z-test dates and circling experiment dates same with normal ship model. And when the change rate increases η= 1.25, the ship model movement have significant changes.In circling experiment,the diameter have significantly increased.Through data analysis,if the ship model has largechange rate,its rudder response is better but circling ability is worse.Therefore, when the use of metamorphosis ship model ship model experiments conducted, the need for ship model scale effect can be corrected so that the ship model and the real ship’s maneuverability similar.