Hostname: page-component-cd9895bd7-fscjk Total loading time: 0 Render date: 2024-12-26T21:58:04.719Z Has data issue: false hasContentIssue false
  • English
  • Français

Numerical Simulations on the Motions of Anchored Capesize Ships

Published online by Cambridge University Press:  25 November 2011

Youjia Zou ,
Chun Shen  and
Xiangying Xi
Youjia Zou*
Affiliation:
(Merchant marine college, Shanghai Maritime University, Shanghai, China)
Chun Shen
Affiliation:
(Merchant marine college, Shanghai Maritime University, Shanghai, China)
Xiangying Xi
Affiliation:
(Faculty of Management, Wuhan University of Technology, Wuhan, China)
*
(E-mail: marscar@126.com)
Get access Rights & Permissions [Opens in a new window]

Abstract

When a ship is moored by a single anchor at the anchorage, its combined motions (i.e. yaw, sway, surge, etc.) are usually induced by external forces. Previous studies have gained some insights into the forces on anchor chains, but the motions for Capesize vessels still need to be further investigated. The length of anchor chain required for safe anchoring also needs to be carefully calculated rather than determined solely by the experience and judgement of Captains. The relationship between the length of chain and water depth, wind force, current velocity and the trim (draught difference forward/aft) requires further study. Our new methods consider all necessary factors which may exert significant influence on ships, including not only the water depth at the anchoring location but also the particulars of the ships, its equipment and the environmental conditions. Here, a numerical simulation model to describe the behaviour of an anchored Capesize ship is presented, with the comparison of results between simulations and real time model tests carried out. A discussion highlights the important features of the methods which provide mariners with theoretical solutions.

Keywords

Numerical simulationLength of chainPeriodAmplitude
Type
Research Article
Information
The Journal of Navigation , Volume 65 , Issue 1 , January 2012 , pp. 145 - 158
Copyright
Copyright © The Royal Institute of Navigation 2011

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

Biguang, H. (1989). Analysis of ship oscillation in low frequency and prediction of ship dragging under the influence of wind and current. Journal of Dalian Maritime University, 15, 129–132.Google Scholar
Boyd, S. P., Ghaoui, L. E., Feron, E. and Balakrishnan, V. (1994). Linear Matrix Inequalities in Systems and Control Theory, Philadelphia, PA: SIAM.CrossRefGoogle Scholar
Chakrabarti, S. (2001). Empirical calculation of roll damping for ships and barges. Ocean Engineering, 28, 915–932.CrossRefGoogle Scholar
Fossen, T. I. (1994). Guidance and Control of Ocean Vehicles, Wiley, New York.Google Scholar
Fossen, T. I. and Grovlen, A. (1998). Nonlinear output feedback control of dynamically positioned ships using vectorial observer backstepping. IEEE Trans. on Control Systems Technology, 6–1, 121–128Google Scholar
Godhavn, J. M., Fossen, T. I. and Berge, S. P. (1998). Nonlinear and adaptive backstepping designs for tracking control of ships. Int. J. Adaptive Control and Signal Processing, 12-8, 649–670.Google Scholar
Heshu, L, Weiqing, J. and Baochun, Y. (1995). Mathematical model of predicting ship dragging. Navigation of China, 1, 128–130.Google Scholar
Jaroslaw, A. (2003). Anchor forces in ship manoeuvring mathematical model. Annual of Navigation, 6, 5–17.Google Scholar
Jiachang, Y., Zuochang, Y. and Yuyang, . (2005). Early warning system of anchor dragging. Journal of Dalian Maritime University, 31, 29–31.Google Scholar
Kim, M. H., Ran, Z. and Zheng, W. (2001). Hull/mooring coupled dynamic analysis of a truss spar in time domain. Int. Journal of Offshore and Polar Engineering, Vol. 11, No. 1, 42–54.Google Scholar
Klaka, K., Krokstad, J. and Renilson, M. R. (2003). Prediction and measurement of the roll motion of a sailing yacht at zero forward speed. Experimental Thermal and Fluid Science, 27, 611–617.Google Scholar
Nesterov, Y. and Nemirovski, A. (1994). Interior Point Polynomial Methods in Convex Programming: Theory and Application. Philadelphia. SIAM Books.Google Scholar
Sariöz, K. and Narli, E. (2003). Assessment of manoeuvring performance of large tankers in restricted waterways: a realtime simulation approach. Ocean Engineering, 30, 1535–1551.Google Scholar
Wenjerchang, Guojang Chen and Yilin, Yeh. (2002). Fuzzy control of dynamic positioning systems for ships. Journal of Marine Science and Technology, 10-1, 47–53.Google Scholar
Wenxian, Gu. (1996). Yaw motion of ships moored with a single anchor. World Shipping, 4, 23–26.Google Scholar
Xiuheng, Wu. (1999). Ship's Maneuverability and seakeeping performance. People's Communication Press, Beijing.Google Scholar