Boundary Layer Measurements and Evaluation of Viscous Resistance Components on Full Hull Forms

Abstract

Three-dimensional turbulent boundary layer on several ship hulls, of which the stern forms are changed systematically, is calculated by a simple integral-type prediction method with small crossflow assumption, and is measured by three-hole Pitot tube in a circulating water channel. The viscous resistance components due to streamwise momentum loss in the boundary layer and stern bilge vortices are evaluated by Himeno's method. The usefulness of the estimation method of viscous resistance is examined in stern-form design problem. A change of the frameline shape at stern affects not only the crossflow in the boundary layer and the strength of the longitudinal vortices, but also the streamwise momentum loss. The viscous resistance becomes small by reducing the fullness of stern shoulder.