Theoretical and experimental comparative analyse on the hydrodynamic resistance of a racing sailboat

Abstract

The large appendages have a very important influence on the hydrodynamic resistance of the sailboats. In this paper, a comparative analyse of the theoretical and experimental results was performed, related to the hydrodynamic resistance of a racing sailboat having an overall length of 12.8 m. The theoretical approach was performed based on the method proposed by Larson and Eliasson. In order to compute the residuary resistance it was used the formulations based on Delft systematic yacht series. The estimation of the resistance components, including the keel, rudder and additional weight influence was carried out based on a computer code in Java language. The experimental model tests have been carried out in the Towing Tank of the Naval Architecture Faculty of “Dunărea de Jos” University of Galati. A 1/10 scaled model with appendages was used for experimental investigations. The level of accuracy of the theoretical prediction was evaluated based on comparative theoretical/experimental diagrams. It was found that the influence of the large appendages is very important and an optimisation procedure becomes mandatory. Moreover, the theoretical methods specific to the preliminary design stage must be improved in order to increase the level of accuracy of hydrodynamic resistance predictions.