Coupled Aerothermoelastic Modeling And Analysis Of Flap For Hypersonic Vehicles

Because of the superiority of breaking through the missile defense system and maneuverability,the hypersonic gliding vehicle is considered to be the perfect vehicle to achieve globle attack.Along with the many advantages of hypersonic flight,the new challenge of aircraft design comes,and the aerothermoelastic coupling problem of hypersonic vehicle is a key bottleneck.Due to its advantages of high pitch control,compact structure and so on,the body flap is often adopted as the aerodynamic control surface and main stability of hypersonic gliding/reentry vehicle.Its control efficiency is very important for the safe flight of hypersonic vehicle,so it is necessary to study the aerodynamic thermo-elastic coupling problem of flap in hypersonic operating condition.On the basis of domestic and foreign research,this paper systematically carries on the study of the coupling characteristics of hypersonic vehicle flap.Aiming at the key problems in aerothermoelastic coupling analysis,the theory and method are studied,including: improved data interpolation algorithm,improved method of quality feedback dynamic grids,the flow field characteristics around flap under hypersonic operating conditions,optimization of flap structure,and study of the characteristics of flap aerothermoelastic response.The specific research is as follows:(1)Aiming at the data interaction problem of different fields on coupling boundary in multiple-field coupling computation,the improvement of the internal projection constant volume conversion method is proposed,which is based on the internal projection constant volume conversion method of non-structured mesh surface element.Its data interpolation ability is verified.(2)To calculate the topological deformation of the field grid in the flow field caused by the boundary movement and deformation in the aerothermoelastic coupling problem,based on the systematic summarization of the improvement method of the main grid quality parameter feedback of elasticity-based dynamic mesh,QC mesh quality feedback method based on mesh area reduction coefficient and grid interior angle constraint is proposed,and the method is verified by comparing the two typical boundary motion modes with rotation and translation.(3)Focusing on the complex and special aerodynamic/thermal environment encountered by the hypersonic vehicle flap,the 2D and 3D flap model are established,and the flow field around the flap with different heights,Mach numbers and obliquity is analyzed numerically.The influence of hinge line gap flow on the load distribution and control efficiency of flap surface is analyzed,the structural parameters of flap model is optimized based on the result of flow field analysis.(4)The unsteady aerodynamic model of the third-order local flow piston theory based on CFD is established.By adopting the hierarchical coupling solution strategy,the study of aerothrmoelastic coupling response of flap geometry model based on C/SiC material is analyzed in this paper,and the structural response characteristics of flap under different heights,Mach numbers and flight angles are analyzed.In addition,the flutter phenomena of hypersonic operating conditions are studied.At last,the work in this paper is summarized and the existing problems and the direction of future research are pointed out.