Trans RINA, Vol 157, Part A3, Intl J Maritime Eng, Jul-Sep 2015
for hulls of L = 110, 130 m the transport efficiency was at least 10% below the highest achieved value at speeds beyond 27 knots.
It is concluded that the total resistance coefficient, the difference between humps and hollows in the resistance curve, the absolute values of sinkage and trim, the fraction of pressure drag and the magnitude of the resulting free
surface elevation decreased with an
increasing demihull slenderness ratio. A hollow in the resistance curve at Fr = 0.37 was identified for all cases where resistance coefficient and pressure drag were at a minimum.
At hump speed (Fr = 0.45) the demihull slenderness
L/1/3 = 11.5 – 13.2 for a wide range of speeds and displacements. L/1/3 may be varied by up to 2 to not exceed the minimal achievable resistance with respect to displacement by 5%.
appropriate for lowest drag with respect to displacement was around 13 for any transom immersion where a demihull slenderness providing low drag was found at
A change in draft altered hull parameters such as the effective slenderness ratio as well as the transom immersion. However, the effect of the first is small, but latter one negatively influences the drag force at low Froude numbers. This effect deteriorates with increasing speeds and at Fr = 0.45 no significant difference in drag normalised by displacement was seen between different transom immersions. Furthermore, an increase in draft leads to a decrease in shear force coefficient that was related to a changing waterline along the hull at speed.
A variation in demihull separation by a half demihull beam led to changes that are within the uncertainty of the results and no significant influence of minor variations in demihull separation ratio was found which agreed with findings of other researchers.
Future work has been proposed to develop a cost model that takes shipping and investment costs for a full life cycle of a ship into account. Additionally the CFD approach will be further investigated for its validity and the flow around transom sterns studied to improve the prediction of the flow around a partially wetted transoms.
6. This research
ACKNOWLEDGEMENTS has
been collaboration research 7. REFERENCES
1. YUN, L. and BLIAULT, A., High Performance Marine Vehicles, Springer Verlag, 2010
2. DAVIDSON, G, ROBERTS, T. R., FRIEZER, S., DAVIS, M. R., BOSE, N., THOMAS, G., BINNS, J.R., and VERBEEK, R., Maximising Efficiency and Minimising Cost in High Speed Craft, Proceedings of International Conference on Fast Sea Transportation, 2011.
3. IMO: MARPOL Annex VI – Prevention of Air Pollution from Ships, 2012.
4. MATSUI, S., SHAO, S.M., WANG, Y. C. and TANAKA, K., The Experimental Investigations on Resistance and Seakeeping Qualities of High-speed Catamarans, Proceedings International Conference on Fast Transportation, 1993.
of Sea
5. MOLLAND, A.F., WELLICOME, J.F. and COUSER, P.R., Resistance Experiments on as Series of High Speed Displacement Catamarans Forms: Variation of Length-Displacement Ratio and Breadth-Draught Ratio, Technical report, University of Southampton, 1994.
6. MCKESSON, C., REMLEY, B., and KARNI, Z.: ‘Ferry Environmental Impact’, Canadian Institute
of 8. TASAKI, Marine Engineers High Performance Vehicles Conference, 2000.
7. EGGERS, K., Über die Widerstandsverhältnisse von Zweikörperschiffen, STG Jahrbuch, 1955. R., A Note
on Wavemaking
Resistance of Catamarans, University of Michigan, Ann Abour, 1962.
9. SATO, R., NOGAMI, H., SHIROSE, Y., ITO, A., MIYATA, H., MASAOKA, K., KAMAL, E. and TSUCHIYA, Y., Hydrodynamic Design of Fast Ferries by the Concept of Super-Slender Twin Hull, Proceedings
Conference on Fast Sea Transportation, 1991.
10. MIYATA, H., OHOMORI, T. and KAMAL, E.M., Hydrodynamical Design of Super- Slender-Twin-Hull Ferries by CFD Techniques, Proceedings
of International Conference on Fast Sea Transportation, 1991.
11. TUCK, E.O. and LAZAUSKAS, L., Small, Low Drag, Solar-Powered Monohulls and Multihulls, Applied Mathematics Technical Report, The University of Adelaide, 1996.
conducted as project between
part of a INCAT,
Revolution Design, MARIN, Wärtsilä and the Australian Maritime College at the University of Tasmania. It was supported under Australian Research Council's Linkage Projects funding scheme (project number LP110100080). Furthermore the authors would like to thank the Tasmanian Partnership for Advanced
(TPAC), especially Matthew Armsby and Kym Hill, for their support with computational resources.
12. DUBROVSKY, V.A. and LYAKHOVITSKY, A.G., Multi Hull Ships, Backbone Publishing Company, 2001.
13. CAPRIO, F. and PENSA, C., Experimental Investigation on two Displacement Catamarans: Systematic Variation of Displacement, Clearance and Stagger, International Journal of Small Craft Technology, 2007.
Computing
14. DAVIDSON, G., ROBERTS, T. R., FRIEZER, S., THOMAS, G., BOSE, N., DAVIS, M.R. and VERBEEK, R., 130m Wave Piercer Catamaran: A New Energy Efficient Multihull Operating at
of International
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©2015: The Royal Institution of Naval Architects
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