Miniature Underwater Glider Hydrodynamic Performance

Abstract

Underwater gliders are becoming an important tool in obtaining in-situ measurements from the ocean. Moving through the water column at slow velocities, their hydrodynamic properties are critical in order to optimize vehicle efficiency and endurance. The hydrodynamic properties also play an important role in defining the allocated budget for the variable buoyancy system of the glider. This paper describes the work performed to optimize the hydrodynamic forces of a small underwater glider, represented in the lift and drag forces of the vehicle, as well as optimizing the angle of attack at which the vehicle is more efficient in producing horizontal motion. The approach used in the analysis is computational fluid dynamics by importing the 3D model of the glider to Ansys Fluent software. The best angle of attack is chosen based on the highest efficiency characterized by the lift-to-drag ratio. Results have shown that the highest lift-to-drag ratio can be obtained at an angle of attack of 10° at speed of 0.2m/s, and 5° at a speed of 0.5m/s.