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Fig.16 Effects of GM on the Turning Parameters
Fig.17 |
Effects of GM on the Overshoot Angles in Zig-Zag Maneuvers |
5. CONCLUSION
Maneuvering characteristics of a 9000TEU container ship were investigated by model tests and numerical simulation. Free running and HPMM tests were carried out at full load and ballast conditions. For a simulation study, mathematical model for 4DOF maneuvering motion was established and applied to predict the maneuvering performance of 9000TEU container ship with hydrodynamic coefficients obtained from HPMM tests. Main conclusions obtained from this study are summarized as follows.
(1) Numerical simulation shows reasonable agreements with free running data. Proposed mathematical model and HPMM test procedure can be used to predict the maneuvering performance of a large container ship.
(2) Container ship shows much different maneuvering performance between at full load and ballast condition. At ballast condition, the ship has very good course keeping and changing performance but worse turning performance due to large trim.
(3) Propeller loading condition affects the maneuvering performance greatly, so that free running test might predict the maneuvering performance more favorably than sea trial.
(4) Large container ship has a good turning performance.
(5) Large container ship has relatively worse course keeping and changing ability. Especially if GM is very low, large container ships are very in danger of not satisfying IMO maneuvering standards for 1st overshoot angle of 10°/10°zig-zag and 20°/20°zig-zag maneuvers.
(6) Since maneuvering characteristics of large container ships are much influenced by GM and roll motion, the effects of roll motion must be included in analyzing and predicting her maneuvering performance.
ACKNOWLEDGEMENT
This study is based on the projects of "Development of Technology projects of on the Maneuverability and Safety for an Advanced Ship" sponsored by Korean Ministry of Science and Technology.
REFERENCES
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[2] IMO, "Resolution A.751(18), Interim Standards for Ship Manoeuvrability", 1993.
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[4] K. Kijima, Y. Furukawa, "Effect of Roll Motion on Maoeuvrability of Ship", Symposium on Forces acting on a Manoeuvring Vessel(MAN '98), 1998.
[5] "MMG Report I, II, III, IV, V", J, of the Society of Naval Architecture of Japan, N0.575(1977), N0.577(1977), N0.578(1977), N0.579(1977), N0.616(1980).
[6] C. G Kang et al., "The Maneuverability of Full Form Ships with Low Speed", Symposium on Forces acting on a Manoeuvring Vessel(MAN'98), 1998.
[7] R.F. Beck et al., "Principles of Naval Architecture", SNAME, 1989.
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