机翼高超音速热颤振有限元分析

摘要

基于热气动弹性的特点，给出考虑温度影响的机翼热颤振有限元分析的一般理论。采用Nastran软件对给定的温度分布热效应下两个典型的高超音速机翼的模态特性和气动弹性稳定性进行有限元分析。计算结果表明，受热结构的模态特性和颤振特性均发生变化。由于温度效应降低弯曲、扭转及弯扭固有频率，还会改变它们之间的相对关系，从而导致颤振临界速度极大地减小。%Based on the characteristics of aero-thermoelasticity, a hierarchical solution process for thermal flutter analysis is presented. Using Nastran software, the natural dynamic characteristic and aero-thermoelasticity of two typical hypersonic wing structures are analyzed involving thermal effect of the given temperature distribution. The results illustrate that both the natural dynamics and the flut- ter characteristics of wings change due to aerodynamic heating. The flutter velocity declines sharply because the high temperature not only makes the first three natural frequencies of structure descend but also changes the difference.of the natural frequencies.