Model Test Study on Parameter Optimization of Stern Flaps of Series Displacement Ships

Abstract

The design of stern flaps generally pursues the resistance reduction of ships at high speed. Moreover, for some surface warships, the parameter selection of stern flap needs is the key consideration due to the wide range of ship speed from cruising to design speed. In this paper, model ship experiments for a series displacement ship are conducted to optimise the configuration of stern flaps. From the model ship resistance and self-propelled model ship experiments, the stern flap impacts to the lowest effective Froude number, resistance of ship, self-propelled status and voyage status are studied. After the analysis of the results and optimizing of the design, the ship with stern flaps has lower resistance and could save 3% and 5% of energy at cruising and design speed respectively. The authors hope the results of this paper could provide help and reference to the design of ship stern flaps in the future.