Optimizing The Circular Disc Underwater Glider’s Pressure Shell And Calculating Pressure Shell’s Assembling Deviation And Analysising Hydrodynamic Effect Of Body Shape

The Circular Disc Underwater Glider has excellent underwater mobility and goodoperating performance.It is capable of long time working in some fixed depth and complex waters.With low cost,long endurance,flexible underwater mobility as well as the advantages of long distance remote control,so it is widely used in scientific observation and exploration and other fields.With the variety of uses of the Circular Disc Underwater Glider,the higher performance is demanded.The weight of the pressure shell accounts for most of the Circular Disc Underwater Glider,so lightweighting pressure shell to guarantee the Circular Disc Underwater Glider to have long endurance;Because of complex environment of deep sea,the pressure shell must ensure compressive strength and structure stability;The Circular Disc Underwater Glider needs better hydrodynamic performance to reduce the movement resistance and increase the lift-drag ratio.Therefore,the calculation of strength and stability of pressure shell,the lightweight of pressure shell and the hydrodynamics optimization of the Circular Disc Underwater Glider’s body shape need to be further studied.In this paper,the structure and shape of a new type of disk-shaped underwater glider are optimized and analyzed.Including:optimization of the pressure shell of ball-ring-ring structure;Optimizing and caculating the assembly deviation of pressure shell;Optimizing the outside shape of the Circular Disc Underwater Glider for better hydrodynamic performance.The main contents are as follows:(1)The optimization of the pressure shell of ball-ring-ring structureThe influences of shell thickness,small ring rib thickness and large ring rib thickness on the compressive strength and structure stability of the pressure shell were analyzed and compared througt the orthogonal test.Opening test on ring rib of the pressure shell,Six hole shapes including the square hole,the ellipse hole,the arch hole,the diamond hole,the round hole and the long round hole were screened by orthogonal test to select the best fit shape;Optimizing holes on the small ring rib and large ring rib in two steps,calculating the design variables througt using the Latin hypercube sampling method,the Kriging response surface fitting is made based on the caculated data,the multi-objective genetic optimization method is adopted to analyze the design variables,finally the pressure shell be optimized under constraint conditions.(2)The optimization and caculation of the ball-ring-ring pressure shell’s assembly deviationSimulating the bolt preload and working pressure(500m depth)on the pressure shell through the finite element software ANSYS,analysing the variation of the compressive strength and structure stability under dislocation assembly,radial assembling deviation,rotate assembly deviation.Caculating the maximum radial assembling deviation and rotational assembly deviation were allowed under constraint conditions.(3)The optimization of the Circular Disc Underwater Glider’s outside shapeThe finite element software FLUENT was used to calculate and analyze the hydrodynamic performance of the Circular Disc Underwater Gider.Caculating the result of motion resistance,lift force,lift-to-drag ratio as well as pitching moment under different diameters,heights and surface saturations.Designing and optimizing the Circular Disc Underwater Glider’s outside shape so that it has better hydrodynamic performance.