超声速流动中功能梯度曲壁板的热气动弹性颤振机理

对高超声速环境中功能梯度曲壁板的热气动弹性颤振机理及分岔特性进行了研究。分别采用活塞理论和Eckert参考焓方法模拟气动力以及气动加热效应,在求解板内二维热传导方程以及考虑温升对材料物性影响的基础上,建立了一个气动加热-气动弹性双向耦合的功能梯度曲壁板的热气动弹性颤振模型。采用有限元方法对曲壁板控制方程进行了数值模拟,着重分析了不同拱高下曲壁板的分岔行为,探讨了拱高变化对曲壁板分岔图的影响,发现了曲壁板颤振三种典型的颤振行为,即:热屈曲、混沌以及规则振动。对初始拱高板厚比为1时,曲壁板的两种规则振动行为进行对比发现,随着马赫数的增大,气动加热效应所引起的热内力会使曲壁板的规则振动更加复杂,同时振动的主振型及频率均会发生变化。

Aerothermoelastic flutter mechanisms of functionally graded curved panel in supersonic flows

Aerothermoelastic flutter mechanisms and bifurcation characteristics of functionally graded curved panel (FGCP) in supersonic flows were investigated. Piston theory and Eckert reference enthalpy methods were used to simulate aerodynamic force and heating, respectively. 2-D heat conduction equation was solved and the impact of elevated temperature on physical properties was considered to build an aerothermal-aeroelastic two-way coupling model of FGCP. Using finite element method, bifurcation diagrams under different arch rise were presented, and the impact of arch rise on the bifurcation diagram was discussed in detail. Three kinds of behaviors such as: thermal buckling, chaos and regular vibration were discovered. Comparative studies of two different regular vibrations were conducted as the ratio of arch rise to panel thickness equaled to 1. It was found that, as Mach number increased to larger values, the regular vibration had higher frequency and different modes due to aerodynamic heating.