showed significant benefits over the fixed conventional keel configuration. For an equal amount of side force production, the total drag was much
lower. The
difference in drag reduction between sailing at a 2° or 4° leeway angle was found to be negligable.
A more realistic situation, with the canting keel at forty degrees to windward and the rudders optimally loaded using the biplane theory, was also tested. In this case it was also found that having the rudders at their optimal angles of attack had a major drag benefit over the fixed, conventional keel case. On the other hand, the benefit of sailing at a greater
drift angle is now more pronounced compared to the “pure” biplane case.
In reality, the situation is more complex because the rudders ought to balance the yacht as well. Thus in many cases it might not be possible to achieve the optimal rudder load distribution.
6. 1.
REFERENCES CLAUGHTON,
considerations 2.
A., OLIVER, C., Design for canting keels, The
International HISWA Symposium on Yacht Design and Yacht Construction, 2004
PAVON, C.L., RODRIGUEZ, R.Z., AND ROJAS, L.P., Hydrodynamic study of a canting keel based appendage configuration, Simposio Internacional
de diseno y produccion de yates de motor y Vela, 2004 3.
MCKEE, C., A CFD Analysis of a Canting Keel Forward Rudder Configuration, MEng thesis, University of Newcastle upon Tyne, 2006
4. 5. 6.
CLAUGHTON, WELLICOME, SHENOI, Sailing yacht design; theory, Addison Wesley Longman Limited, 1998
LARSSON, L., ELIASSON, R.E., Principles of yacht design; 2nd edition, Adlard Coles Nautical, 1999
KEUNING, J.A., SONNENBERG,U.B.,
Approximation of the Calm Water Resistance on a Sailing Yacht Based on the Delft Systematic Yacht Hull Series, 14th Chesapeake Sailing Yacht Symposium, SNAME, 1999
7.
BEUKELMAN, W., KEUNING, J.A., The influence of Fin Keel Sweep-back on the Performance of Sailing Yachts, 5th HISWA Symposium, 1975, Amsterdam
8.
VAN OOSSANEN, P., Predicting the speed of sailing yachts, SNAME Transactions vol. 101, pp. 337-397, 1993
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©2007: Royal Institution of Naval Architects
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