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Abstract

During the design process of an offshore vessel, the DP system is not representing one of the primary constraints for the general arrangement of the vessel. Usually the location of the thruster devices is driven by the internal spaces available, i.e. the thrusters position is not optimised to reach the maximum capability. This is also true for a conversion of an existing vessel. Nowadays almost all offshore vessels require the installation of a DP system on board, means that it could be worthy to study more in detail the arrangement of the thrusters in such a way to maximise the capability of the vessel to keep position with a determined amount of power installed on board. In the present work a procedure aimed to find an optimal thruster location on the hull during early design stage will be presented. Using a quasi-static approach for DP capability evaluation, an optimisation procedure based on genetic algorithm has been developed, considering the constraints given by the vessel geometry. The discussion is supported by a test case on a reference vessel, were the original layout is compared with two possible optimised configurations.

Keywords

Dynamic positioning thrusters positions optimisation offshore vessels

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References

ABS, Guide for dynamic positioning systems, Technical report, American Bureau of Shipping, 2014.

P.A.

Absil,

Mahony and

Sepulchre, Optimization Algorithms on Matrix Manifolds, Princeton University Press, 2008. doi:10.1515/9781400830244.

American Bureau of Shipping ABS, Guide for dynamic positioning systems, 2013.

Cozijn and

Hallmann, The wake flow behind azimuthing thrusters; measurments in open water, under a plate and under a barge, in: Proceedings of OMAE 2012 Conference, Rio de Janeiro, 2012.

Det Norske Veritas DNV, Rules for classification of ships, 2011.

DNV-GL, Assessment of station keeping capability of dynamic positioning vessels, 2016.

DNV-GL, Assessment of station keeping capability of dynamic positioning vessels, 2018.

Ekstrom and

D.T.

Brown, Interactions between thrusters attached on a vessel, in: Proceedings of OMAE 2002 Conference, Oslo, 2002.

J.H.

Holland, Adaptation in Natural and Artificial Systems, University of Michigan Press, 1975.

10.

Lehn, Thruster interaction effects, Technical report, NSFI, Marintek, 1980.

11.

Mauro and

Gaudiano, Station-keeping calculations in early design stage: Two possible approaches, in: Proceedings of NAV 2018 Conference, 2018.

12.

Mauro and

Nabergoj, Integrated station-keeping and seakeeping predictions, in: 16th International Congress of the International Maritime Association of the Mediterranean IMAM 2015, Taylor and Francis , eds, Pula (Croatia), 2015.

13.

Mauro and

Nabergoj, Smart thrust allocation procedures in early design stage dynamic positioning predictions, in: Proceedings of the 18th International Conference on Ships and Shipping Research NAV 2015, Lecco, Italy, 2015.

14.

Mauro and

Nabergoj, Advantages and disadvantages of thrusters allocation procedures in preliminary dynamic positioning predictions, Ocean Engineering 123 (2016), 96–102. doi:10.1016/j.oceaneng.2016.06.045.

15.

McCall, Genetic algorithms for modelling and optimisation, Journal of Computational and Applied Mathematics 184 (2005), 205–222. doi:10.1016/j.cam.2004.07.034.

16.

Nabergoj,

Ardavanis,

Cok and

Faldini, DP upgrade after vessel refitting, in: Proceedings of 10th International Conference on Hydrodynamics, Krylov shipbuilding Research Institute Ed., St. Petersburg (Russia), 2012, pp. 1–6. ISBN 978-5-903002-36-8.

17.

Nienhuis, Abnalysis of thruster effectivity for Dynamic Positioning and low speed manoeuvring, PhD thesis, Technische Universiteit Delft, 1992.

18.

Serraris, Time-domain analysis for DP simulations, in: Proceedings of OMAE Conference, Honolulu, Hawaii, 2009.

19.

Smogeli,

Trong,

Borhaug and

Pivano, The next level DP capability analysis, in: Proceedings of Dynamic Positioning Conference, 2013.

20.

The International Marine Contractors Association, IMCA, Specifications for DP capability plots, London, UK, 2000.

21.

Wichers,

Buitema and

Matten, Hydrodynamic research and optimizing dynamic positioning system of deep water drilling vessels, in: Offshore Technology Conference, OTC 8854, Houston, Texas, USA, 1998.

22.

A.M.

van Wijngaarden, Upgrades and conversions of floating offshore units, in: International Conference on ICSOT: Developments in Fixed and Floating Offshore Structures, Royal Institution of Naval Architects, 2012.

23.

S.Z.

Yang,

Wang and

Sun, Optimal thrust allocation logic design of dynamic positioning with pseudo-inverse method, Annals of Shanghai Jiaotong University 16 (2011), 118–123. doi:10.1007/s12204-011-1104-9.

Optimal thruster location on offshore DP vessels

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