Structure Thermal Response Analysis In The Aeroheating Environment

Structure thermal response is referring to the structure dynamicresponse in high temperature environments.Hypersonic flight vehicles often suffer serious deteriorationenvironment，such as aero heating and so on， that make flight vehicles’thin structures suffer tremendous heat loading, and the structures’ inherentcharacteristics will change in such an environment. Since thin structuresare widely applied in modern hypersonic flight vehicles, the correspondingaero heating problems become increasingly serious, and one of the keyproblems and concerns of modern hypersonic flight vehicle designing.The heat flux generated by aero heating may cause the structuretemperature increase rapidly, and then influence the structure’s dynamiccharacteristics, i.e. the stiffness of structure which will decrease as thetemperature increases rapidly. Structure thermal modal analysis, which canreflect the extent of this influence due to heat flux to the structures, is animportant analysis method which figures out how the heat flux influencesthe structures.Firstly, current paper uses a code simulating the aero heatingenvironment, gets the wall heat flux of structure, and provides a morerealistic thermal load for thermal response analysis. Secondly, thermalmodal analyses for typical thin structures are carried out with analyzing thechange of the first three modal of vibration amplitude and naturalfrequencies under the cold wall heat flux and hot wall heat flux,respectively. Note that the latter analysis on the hot wall heat flux wascalculated by fluid-structure coupling method. Finally, we analyze thetemperature fields and thermal responses of three kinds of typical thin structures in hypersonic environment. At the same time, the same analysison a kind of wing structure in a complete flight trajectory environment isdone.The results show that: the heat flux calculated by fluid-structurecoupling method is suitable for structure thermal analysis and thermalmodal analysis in aero heating environment. In the aero heatingenvironment, the structures’ temperature will increase by a large scale,resulting in the occurrence of thermal stress inside the structure, and thegradual reduction of its inherent frequency as the temperature of thestructure rises.Structure thermal response analysis is beneficial for furtherunderstanding the dynamic coupling between aero heating and thermalprotection system. And its results possess important reference value fordesigning thermal protection system of modern hypersonic flight vehicles.