Structure Design And Analysis Of A Small Disk-Shape Autonomous Underwater Helicopter

The ocean is rich in resources,and the exploration of the ocean has received more and more attention in recent years.For a long time,marine exploration requires tools,and submersibles are one of the commonly used marine exploration tools.Most of the submersibles are cylindrical and streamlined,while the disk-shape submersibles are less studied.A disk-shape submersible that is autonomous and achieve free movement and stable advancement in a small scale is even more lacking in research.The disk-shape submersible has the advantages of stable motion and good operability and maneuverability in harsh working environments.This paper focuses on designing and researching a circular disc autonomous submersible with good stability.Through theoretical design analysis and digital simulation research,a small autonomous underwater helicopter with good motion stability is realized.The content of this paper is arranged according to the logical sequence of shape structure design,motion simulation analysis and experimental verification:the design of the shape draws on the design idea of Myring shape,and proposes a quantitative design scheme that satisfies both high stability and large internal space requirements,which is determined by simulation.A small autonomous underwater helicopter with a flat,convex shape profile on the edge.After determining the shape,from the perspective of improving the stability of motion,through the analysis and design of the center of gravity and the center of buoyancy,the position of each sealed cabin and buoyancy material is evenly arranged,and the sealed cabin and buoyancy regulating device are designed.The amount of buoyancy material is calculated.Motion is simulated via CFD simulation.The two factors affecting the stability,deviation of the propeller output and the speed of the submersible,were studied under the same conditions.The thrust difference of the propeller will cause the submersible to yaw,affecting the linear stability of the submersible during the movement,and the speed of movement will affect the attitude stability of the submersible during the movement.Finally,it is the prototype experiment.Before the launching experiment,the prototype carried out a reasonable analysis and experiment on the thruster thrust problem and the waterproof seal problem.After the underwater motion experiment,the experimental data was recorded by the stopwatch and internal sensor data.Acquired and further demonstrated the stability of the small autonomous underwater helicopter's athletic ability through experiments.Through the above work,we can get:The shape of the circular disk submersible with high stability and large internal space can be obtained by expanding the center of the circular disk submersible.However,since the disc type is a revolving body,the disk-shape small autonomous underwater helicopter is prone to revolving,and the thrust difference between the propellers on both sides gradually accumulates the lateral deviation in the linear motion,and adopting direction adjustment every 1 m to 1.5 m per second can achieve good linear motion stability and motion efficiency at the same time;when the small autonomous underwater helicopter has a large moving speed,it will produce a pitching attitude,which is not conducive to the stability of the motion.Therefore,the moving speed of the disk-shape submersible should be limited to a certain range to maintain good motion stability.For small autonomous underwater helicopters,the speed should be 1 knot,that is,within 0.5m/s,and the optimal speed is about 0.3m/s.The experiments of small autonomous underwater helicopter show good sports performance,good stability.And working in poor water quality environment proves that the design is reasonable and reliable.In summary,through the design,simulation and experiment in this paper,a small autonomous underwater helicopter with independent control ability and free movement and stable advancement in a small scale is obtained.In addition,a design scheme was proposed for the shape design of the disk-shape submersible,which contributed some strength to the research of the disk-shape submersible.