Research On Optimization Of Multi-parameter Of Blended-wing-body Underwater Glider High Lift-to-drag Ratio

The underwater glider is an autonomous underwater detection device that relies on its own net buoyancy to achieve floating and submerging motions.It has the advantages of low noise and strong endurance,making it a powerful tool for underwater exploration of the ocean.However,the traditional underwater glider adopts the layout form of adding small wings on both sides of the revolving body configuration,which results in the low lift-to-drag ratio of the traditional glider,and the gliding efficiency is difficult to guarantee.In order to further improve the hydrodynamic performance of the underwater glider and improve the glide efficiency,research on the shape optimization of the Blended-wing-body underwater glider(BWBUG)is carried out.First,complete the overall design of the Blended-wing-body underwater glider.In order to make the BWBUG before and after optimization have engineering applicability,the modular and block design concept is adopted,combined with CFD numerical simulation and glide motion conclusions,the overall design of the Blended-wing-body underwater glider and the design and performance analysis of each system module are completed.Through the virtual assembly of the glider,the statics calculation and balance check have been completed,which provides guidance for the construction of the glider control system and the manufacture and assembly of the prototype.Guided by the finite element method,the calculation of the strength and stability of the pressure cabin has been completed to ensure that the glider can withstand the pressure of the maximum water depth of 600 m.Innovatively proposed the control method of the roll attitude adjustment system and the emergency handling system,which provides a new design direction for the system design of the blended-wing-body underwater glider.Secondly,complete the numerical simulation of the initial Blended-wing-body underwater glider.The force analysis of the glider is carried out and based on the theory of viscous fluid,the sliding grid method is used to solve the hydrodynamic performance of the underwater glider at four set speeds and different angles of attack.Quantitative changes of the hydrodynamic parameters with the angle of attack are given,and the optimal sailing angle of attack of the underwater glider is determined.Through the analysis of the pressure field and velocity field of the underwater glider,the pressure distribution law of the Blended-wingbody underwater glider is clarified,and the direction of hydrodynamic shape optimization is pointed out.Then,complete the glide performance analysis of the initial Blended-wing-body underwater glider.The glide motion analysis in the longitudinal plane of the Blended-wingbody underwater glider was carried out,and the motion parameters of the typical glide state were predicted.The best anti-current capability and working performance of the Blendedwing-body underwater glider is analyzed.It provides data support for the glider’s attitude adjustment and buoyancy system design.Finally,complete the parametric modeling and shape optimization design of the Blended-wing-body underwater glider.Draw lessons from the XRay appearance design experience of a generation of Blended-wing-body underwater gliders,and determined a plan for constructing a wing-body-integrated underwater glider model with a combination of plane shape and airfoil profile.Relying on the CAESES software platform,the establishment of a fully parametric fine model of the Blended-wing-body and the hydrodynamic hull of the underwater glider was completed.And through the software optimization platform,the combination optimization algorithm strategy is adopted to obtain the maximum lift-to-drag ratio as the goal,and the internal loading requirements are fully considered for optimization research.