semidisplacement of hull form

10th International Conference on Fast Sea Transportation
FAST 2009, Athens, Greece, October 2009

MOTOR YACHT HULL FORM DESIGN FOR THE DISPLACEMENT
TO SEMI-DISPLACEMENT SPEED RANGE
Perry van Oossanen1, Justus Heimann2, Juryk Henrichs3, Karsten Hochkirch4
1

Naval Architect, Van Oossanen & Associates bv, Costerweg 1F, 6702AA, Wageningen, the Netherlands
2
Head of Hydrodynamics, FutureShip GmbH, Benzstr. 2, D-14482 Potsdam, Germany
3
Hydrodynamicist, Van Oossanen & Associates bv, Costerweg 1F, 6702AA, Wageningen, the Netherlands
4
Vice President Fluid Engineering, FutureShip GmbH, Benzstr. 2, D-14482 Potsdam, Germany

ABSTRACT
Nowadays, the design of luxury motor yachts is focussed on ever higher speeds. Froude numbers between 0.6 and 0.8 are no longer an exception. The typical load profile of a motor yacht often consists of long range cruising at low speeds and only short periods of time at higher and maximum speeds. This indicates the need for focussing hull design over the entire speed range rather than on maximum speed only. For this purpose the concept of the Fast Displacement Hull Form (FDHF) is introduced.
The concept and the use of design features that have a large effect on the resistance over the speed range, such as the area of the immersed transom, bulbous bows, trim control and spray rails are discussed. A design methodology using a formal optimization method for the bulbous bow is described and it is shown that bulbous bows are also effective in the semi-displacement speed range.
A comparison of the FDHF concept, in terms of resistance, with model tests of displacement and semidisplacement motor yachts, shows a significant resistance improvement over the entire speed range, but especially at displacement speeds when comparing to semi-displacement hull forms. Issues such as stability, interior space and building cost are addressed.

NOMENCLATURE
CP
CTL
Δ
FN,L
FN,T
FN,V

Prismatic Coefficient
Telfer Coefficient

References: Abt, C. and Harries, S. (2007). ‘A new approach to integration of CAD and CFD for naval architects’, 6th COMPIT, Cortona, pp.467-479, Bailey, D. (1974). ‘Performance Prediction – Fast Craft’. Royal Institution of Naval Architects, RINA Occasional Publications No Bailey, D (1976). ‘The NPL High Speed Round Bilge Displacement Hull Series’. Maritime Technology Monograph, No Bertram, V. (2000). ‘Practical Ship Hydrodynamics’, Butterworth & Heinemann Blount, D.L Blount, D.L. and McGrath, J. (2009). ‘Resistance Characteristics of Semi-Displacement Hull Forms’. Royal Institution of Naval Architects, Proceedings of the Symposium on the Design, Construction and Operation of Deng, G.B., Guilmineau, E., Queutey, P., Visonneau, M. (2005). ‘Ship Flow Simulations with the ISIS-CFD Code’ Deng, G.B., Queutey, P., Visonneau, M. (2006). ‘A Code Verification Exercise for the Unstructured Finite Volume CFD Solver ISIS-CFD’ Doctors, L.J. (2006). ‘Influence of Transom-Hollow Length on Wave Resistance’. International Workshop on Water Waves and Floating Bodies 21, Loughborough, UK, 2006. Dudson, E. and Harries, S. (2005). ‘Hydrodynamic fine-tuning of a pentamaran for high-speed sea transportation services’, Int FutureShip / Fluid Engineering (2009). ‘FS-FLOW, FS-SHALLOW, FS-WAVES, FS-OPTIMIZER, FSEQUILIBRIUM Release and Users Manuals, Rel.09x’, FutureShip GmbH, http://www.fsopt.com. Harries, S., Hinrichsen, H. and Hochkirch, K. (2007). ‘Development and application of a new Form Feature to enhance the Transport Efficiency of Ships’, Jahrbuch der Schiffbautechnischen Gesellschaft, Heimann, J. and Harries, S. (2003). ‘Optimization of the Wave-Making Characteristics of Fast Ferries’, 7th Int. Conference on Fast Sea Transportation (FAST 2003), Ischia (Gulf of Naples), Italy, http://www.fsopt.com/downloads/2003_FAST_HeimannHarries.pdf. Heimann, J., Hutchinson, B. L. and Racine, B. J. (2008). ‘Application of the Free-Wave Spectrum to Minimize and Control Wake Wash’, SNAME Annual Meeting & Expo, Houston, Hochkirch, K. and Bertram, V. (2009). ‘Slow Steaming Bulbous Bow Optimization for a Large Containership’. Keuning, J.A. (1984). ‘Comparison of the Resistance and Motions in Waves of a Round Bilge and Hard Chine Model of a High Speed Displacement Ship’ Technology, No. 612, 1984. Telfer, E.V. (1963). ‘The Design presentation of Ship Model Resistance Data’. North East Coast Institution of Engineers and Shipbuilders, Transactions Vol