Numéro : 2044 - Year : 1987
The influence of trim and bow induced wave profile on the performance prediction of a 12m yacht
G.TRINCAS, Doctor, Senior Researcher, of the Institute of Naval Architecture, Trieste, Italy
I. G RUBISIC, of the Department of the Naval Architecture, Zagreb, Jugoslavija
The most modern dynamometer systems for testing sailing yachts models allow five degrees of freedom, whilst the well-developed velocity prediction programs refer to a system with three degrees of freedom only Furthermore, the main design parameters of the canoe body are considered fixed without any actual variations depending on speed, trim and heeling
In this paper the authors analyse the effect of wave making profile and trim on the hull geometry of a typical 12 Metres Class by systematica11y testing a model in a small towing tank These affect all the hydrostatic particulars which depend on draught and hence the hydrodynamic resistance at every sailing point of interest.
For a given stability, the choice of the optimum design waterline length and canoe body form with respect to the best windward performance can be correctly found since the preliminary design stage. The convenience of introducing a fourth degree of freedom in the velocity prediction program is discussed as well