高超声速全动舵面的热气动弹性研究

根据分层求解原理对考虑舵轴及舵轴与机身间隙影响下的高超声速飞行器全动舵面进行了热气动弹性分析. 采用计算流体力学（CFD）方法求解N-S 方程计算舵面周围的热环境，在该温度分布下根据结构壁面温度计算热流，应用傅里叶（Fourier）定律确定结构热传导过程及其内部温度分布，进而分析结构考虑热应力和温度对材料属性的影响下的模态固有特性，结合基于CFD 技术的当地流活塞理论，在状态空间中对舵面进行了热气动弹性分析. 结果表明，气动加热效应改变了结构的固有频率以及弯扭耦合频率之间的间距，进而改变了结构的颤振速度和颤振频率；随着热传导的进行，结构固有频率和颤振频率先快速减小后基本保持不变，弯扭耦合频率之间的间距和颤振速度则先快速减小后略有上升；舵轴及舵轴与机身间隙的存在对舵面的固有频率、颤振频率、颤振速度都产生了影响，使其最大下降了6%. 

STUDY ON AEROTHERMOELASTICITY OF A HYPERSONIC ALL-MOVABLE CONTROL SURFACE

An aerothermoelastic analysis of a hypersonic all-movable control surface, in which the effects of the axis and the gap were considered, was carried out based on the hierarchical solution process. The CFD (Computational Fluid Dynamics) method was firstly used to solve the N-S (Navier-Stokes) equations and get the thermal environment around the control surface. Then the wall heat flux was calculated based on the surrounding temperature and the wall temperature. The heat conduction was solved using Fourier's law to obtain the structural temperature distribution. In addition, the structural inherent characteristics considering thermal stress and material degradation were analyzed. The unsteady aerodynamic forces were calculated through local flow piston theory based on CFD. Lastly the flutter was analyzed by state space method. The results show that changes of natural frequencies and pitches between the bending frequencies and the torsion frequencies due to the aerodynamic heating result in changes of the flutter speeds and the flutter frequencies; with heat conduction going on, the natural frequencies and the flutter frequencies become unchanged after a rapid decrease, and the pitches increase slowly after a rapid decrease; the natural frequencies and the flutter frequencies as well as the flutter speeds firstly decrease and then increase with time when only thermal stress takes effect; the axis and the gap can lead to decrease in the natural frequencies, the flutter frequencies and the flutter speeds and the maximum reduction reaches to 6%.