Investigation of the Influence of Bulbous Bow on the Wake Field and Power Demand

Abstract

Ship resistance is one of the main factors affecting the ship's design and the selection of her propulsion system. Propeller designers must accurately estimate the wake field in waves behind the ship in order to create effective propeller geometry under actual operating circumstances. In this study, various bulbous bow shapes of the DTMB 5415-51 surface combatant were numerically investigated using a CFD method. The aim of the study is the evaluation of the impact of the bulbous bow shape variation not only on the ship resistance but also on the wake field as well as on the propulsion performance. Three-dimensional URANS numerical flow simulations of combatant ship were applied and systematically altered bow shapes in calm water and waves were carried out. For the validation of the numerical simulations, three alternative mesh sizes for Froude numbers ranging from 0.10 to 0.40 are considered; results are compared with those of the towing tank in terms of wave field, resistance coefficients, and propulsive efficiency. The results show a considerably different hydrodynamic characteristics for different bow shapes.