The Numerical Research On Fluid-structure Interaction Of High-aspect-ratio Flexible Wings

With the development of the material, energy and control technology, high altitudelong endurance UAV are highly regarded by many countries. A prominent feature ofhigh altitude long endurance UAV is the lightweight high-aspect-ratio structures, thestiffness of the structure is far less than that of conventional aircraft. Thus, thesestructures of would appear large deformation undertake the aero-force, the deformationwill be showing a strong geometrical nonlinearity，At the same time, it will be verydifferent of the aerodynamics distribution of flexible wings compared to rigid ones.Specially. To solve this problem, combination of the structure and aerodynamic isneeded, namely fluid-solid interaction problem. At present, the weak coupling approachfor the fluid and structure interaction, which need the structure the fluid and structuremodeling and calculation independently, is relatively mature. Then, the couplinganalysis is completed through the interface data transmission and dynamic mesh.Therefore, the key to this method is the accurate analyze of structure and flow field andrealization of the coupling processes.Therefore, this paper takes high-aspect-ratio flexible wing as the research object,the fluid-structure interaction as the main line. The following aspects are researched inthis paper:(1) Summed up the characteristics of the aircrafts which owe high-aspect-ratiowings, and concluded the methods that are used in the research to the issue offluid-structure interaction.(2) Paid an attention to nonlinear structure and low Reynolds number aerodynamicperformance through combination theoretical analysis and numerical simulations.(3) Analyzed the key technology and difficulty in the fluid-structure interactionanalysis and simulation, especially, the coupling approach of the equations that take acontrol to the fluid and structure; data interpolation methods between non-match meshes,which should be suitable for the large deformation; the distributed and parallelsimulation technology.(4) Verified the feasibility and validity of the coupling method used in this paperby comparing with the analysis results and literatures. Then, this paper analyzed theperformance of the flexible wings by the one-way coupling and two-direction couplingmethod and two-directions method.