Problem Study Of Hypersonic Control Surface Aerothermoelastic

With its important military strategic significance and extensive civil prospects,hypersonic vehicle has been highly valued by all countries in the world and has become a research hotspot in the aerospace.Complicated flow phenomena such as aerodynamic heating,high-temperature effects,and strong shock interference in hypersonic flows place the structure in a severe thermal environment,which induces serious aerothermoelastic problems.When analyzing and solving this kind of problem,it is necessary to consider aerodynamics,aerodynamic heat,structural heat transfer,and thermal radiation.It is a typical multidisciplinary problem.Solving the problem of aerothermoelasticity using fluid-solidthermal multi-field coupling technology has gradually become one of the key technologies for the development of the vehicle.According to the structural characteristics of hypersonic vehicles,a typical hypersonic control surface model is designed.The local flow piston theory based on CFD technology and the reference enthalpy method based on Prandtl boundary layer theory are used to solve the flow parameters,and the data exchange between multi physical fields through the coupling platform.The static aerothermoelastic trim and modal analysis are carried out.The results show that the structure stiffness is greatly reduced and the structure deformation is caused by the aerodynamic heating.And,the bending-torsional mode of the structure approach each other.Taking thermal trimming results as initial conditions,the aerothermoelastic response of control surface is calculated by mode superposition method.Appling the perturbation,the flutter velocity range is determined by the displacement response of the sensitive position.The results show that,the aeroelastic characteristics are changed and the flutter speed decline by the aerodynamic heating effect,and the change of material properties plays a leading role.The temperature distribution function of the control surface model is constructed to calculate the effect of transition position on aerothermoelasticity.The results show that the transition from laminar flow to turbulent flow results in the increase of temperature gradient inside the structure and the formation of local thermal buckling.When the additional geometric stiffness matrix plays a leading role in the total stiffness change of the structure,it seriously affects the dynamic characteristics and flutter characteristics of the structure.