Hydrodynamic Characteristics Analysis And Optimal Design Of Underwater Flexible Foldable-Wing

At the beginning of this century,the development of ocean observation has come to the era of intelligent observation represented by underwater vehicle.Underwater glider is a widely used observation underwater vehicle,which has become the first choice for large space-time and high density ocean observation in recent years.However,the traditional underwater glider usually adopts ship-based arrangement,and in most cases,the distribution efficiency is low.Therefore,if the underwater glider can have the ability of multi-platform rapid deployment,especially tubular launch(airdrop,subsurface emission,etc.),and combined with the characteristics of its autonomous mobile observation,the The ability of emergency maneuvering observation in sudden sea area is greatly improved.In order to solve the above problems,the concept of underwater flexible foldable-wing is proposed.In this paper,focusing on the key scientific problem of "interaction mechanism between hydrodynamic performance of airfoil and navigation efficiency of underwater glider",aiming at the existing problems and constraints of traditional rigid wing,based on the idea of bionic principle,this paper puts forward the idea of underwater flexible foldable-wing replacing the traditional rigid fixed wing to provide lifting force of underwater glider,and this paper mainly studies three aspects:rigid-flexible fluid-solid coupling model and its constitutive relation,hydrodynamic performance and range comprehensive evaluation model and structure design of flexible foldable wing,explore and solve the key basic problems involved.In addition to the effectiveness verification and performance evaluation based on computer simulation,some of the research results are verified by underwater environment physics experiments.The research results of the project provide important technical support for the rapid deployment and covert deployment of underwater gliders by multi-platform,and also provide a theoretical basis for the development of similar underwater mobile observation platforms.The specific research results of this paper are as follows:(1)The action mechanism of flying fish pectin is studied and its bionic parameters are extracted.A set of underwater flexible foldable-wing design scheme based on bionic principle is proposed,which is suitable for high efficiency gliding of underwater glider by means of parametric modeling.(2)The Viscoelastic Constitutive equation of foldable-wing and the adaptive dynamic calculation model of flow field are established.The computational fluid dynamics simulation analysis is carried out by using CFD method by STAR-CCM+software,and the hydrodynamic coefficients necessary for the study of hydrodynamic characteristics are calculated.The hydrodynamic coefficients and the Viscoelastic Constitutive equation of the foldable-wing can be used to characterize the relationship between the hydrodynamic force of the foldable-wing and its motion state.(3)The evaluation index of the navigation performance of the underwater glider is established,and the navigation performance of the foldable-wing underwater glider and the fixed-wing underwater glider is compared and evaluated.(4)The structural design analysis and optimization of foldable-wing are carried out,including the structural design and analysis of wing folding device and pressure shell,the selection of wing surface material and wing shape.(5)The gliding performance of foldable-wing is verified by underwater environment physics experiment.In this paper,the pool experiment will be carried out to obtain the motion data and motion attitude of the foldable-wing underwater glider,and the validity verification and performance evaluation will be carried out.