Influence of hull geometry on self-propulsion performance of vector-propelled streamlined AUV with a ducted propeller

Abstract

Vector-propelled streamlined autonomous underwater vehicles (AUVs) have attracted considerable attention owing to their superior maneuverability. This study investigates the influence of hull geometry on the self-propulsion performance of a vector-propelled streamlined AUV with a ducted propeller. Firstly, the numerical models for both vector-propelled streamlined AUVs and ducted propellers are presented. Secondly, a novel self-propulsion prediction method is developed using computational fluid dynamics (CFD) and an overset mesh technique. This method is validated using a model experiment. Finally, self-propulsion simulations are conducted under horizontal, vertical, and spatial motion conditions. The effects of the head length, head shape index, and length-to-diameter ratio on the self-propulsion performance are discussed. The results show that: (1) the head shape index affects the hydrodynamic drag in the surge direction during horizontal turning, whereas the length-to-diameter ratio affects the drag in the sway and yaw directions. (2) During vertical turning, the head shape index affected the drag in the surge direction, and the length-to-diameter ratio affects the drag in the heave and pitch directions. (3) The length-to-diameter ratio significantly affects turning diameter, period, and vertical pitch during spatial motion. As the length-to-diameter ratio increases, the hydrodynamic drag increases in the surge, heave, sway, and yaw directions.