Experimental Study of Resistance and Flow Due to Difference of Entrance Forms

To investigate an influence of local modification of entrance form on resistance and flow, the authors made the resistance tests and the flow measurements on the four model ships, with different radius at stem. For these studies the authors have developed a resistance test system using divided model ships in order to obtain bow resistances separately.As the result of these experiments, the authors found significant differencies of the bow resistance and flow around the bow and showed an optimum radius at stem. Learning the results of flow measurements, it could be considered that vortices at bow play important role in these differencies of resistance.Lastly the authors tried to explain the relation among entrance form, vorticies and resistance, by Hawthorne's theory. Inspite of assumption including the theory, the results of calculation showed good agreement with experimental ones in some points.