The Characteristics Research Of Large Buoyancy-driven Underwater Gliders

The Autonomous Underwater Glider (AUG) is a special type of the AutonomousUnderwater Vehicle (AUV). Applying the slight change of its buoyancy and converting thevertical motion into the horizontal motion by matching the wings, its forward motion can bedriven with the low electric consumption, while the overlength course and the high enduranceare realized. Namely, it is possible that the marine environmental data can be obtained via thesectional measurements in the seawater by equipping with the relevant sensors and the marineenvironment can be monitored by installing the appropriate checkout equipment.A new AUG with the larger buoyancy-driven is designed by setting the largebuoyancy-driven device in the midship and optimizing the linear anti-drag to glide at by the lowspeed (0.5kn), the medium speed (1kn), the high speed (2kn) and the multi-gesture (20°～40°). And this glider also can be used in the sea with the2kn speed and the great change of theseawater density, which can meet the autonomous, real-time and maneuvering measurement ofmany marine factors of our national marine environment with the high ocean current, andpromote the ability of the national AUG to monitor the complex marine environment and protectthe information as well.The paper is mainly about the shape design and optimization of the AUG and thecharacteristic analysis of the lager buoyancy-driven AUG, which includes the choke characterand the controllability under the conditions of pitch and yaw. Then, the relevant designparameters and the system motion character are identified by establishing the dynamic model ofthe AUG and analyzing and simulation calculating the dynamic flows. The correctness of thedesign, model and simulation of the AUG and the effectiveness of the function implement areconfirmed by combining the pool trial and the sea trial of the AUG. The primary researchachievements in the paper are as follows:(1) Design and optimize the shape of the AUG by adopting the standard Genetic algorithm.(2) Analyze the characters and obtain the parameters of each hydrodynamic force byapplying the Computational Fluid Dynamics (CFD) software FLUENT to calculate the dynamicflow of the designed model.(3) Design a buoyancy adjusting device with the largely adjusting ability, which lays thefoundation for the choke character of the AUG.(4) Establish the dynamic model of the AUG, and analyze the controllability of the AUG under the conditions of pitch and yaw, and research the relationship between the designedparameters and the motion performance of the AUG, and obtain the speed range and the directionrange of the AUG, and indentify the relevant designed parameters.