Effects of a propulsor on the maneuverability of an autonomous underwater vehicle in vertical planar motion mechanism tests

Abstract

The effects of a propulsor on the hydrodynamic forces acting on an autonomous underwater vehicle (AUV) were investigated by towing tank model tests. A mathematical maneuvering model using a whole vehicle model was established, and captive model tests using vertical planar motion mechanism equipment were performed to obtain maneuvering coefficients. The Reynolds number of the full scale test model in the operation condition was 4.12 × 106, and the revolution rate of the propulsor was fixed at the self-propulsion point. The forces on the body and control fins were measured in static drift, control fin deflection, pure heave and pure pitch tests with and without the propulsor. The propulsor effects on the hydrodynamic force and moment were identified as spatially irregular thrust, flow acceleration around the control fins, and added mass of the propulsor. In the simulation using the component model where the propulsor effect considered as a constant thrust, the maneuverability of the AUV was overestimated compared to that of the whole vehicle model. Thus, the mathematical maneuvering model should consider propulsor-hull interactions.