气动加热环境下大攻角翼面超音速颤振分析

Analysis of supersonic flutter of the wing with high angle of attack with aerodynamics heating

研究大攻角翼面超音速热颤振的分析方法,内容包括气动加热、温度场、热应力和热模态分析,大攻角翼面非定常气动力计算和热颤振分析。提供了一套从流场分析开始到颤振临界参数搜索的一体化热颤振工程分析方法。气动力方面,应用激波膨胀波理论计算大攻角翼面的当地流场参数;应用参考焓方法计算大攻角翼面气动加热的热流密度;以当地流活塞理论计算翼面超音速非定常气动力。结构方面,利用有限元方法进行翼面瞬态温度场和热模态分析,然后用模态叠加法建立颤振运动方程;应用状态空间法和时域递推积分的方法求解颤振运动方程。工程实例的热颤振分析表明,在Ma>3的高马赫数下热颤振临界动压比常温的颤振临界动压明显下降,高马赫数下翼面的热颤振分析在工程设计中值得重视。

The research about the analysis approach of thermo-flutter of supersonic wing with high angle of attack is presented, including the introduction of mathematical model and solution procedure of thermo-flutter, and the calculation and analysis of aerodynamics heating, temperature field, thermal stress and thermo-mode as the input of thermo-flutter analysis and design. Therefore, the integrated engineering analysis method of thermo-flutter which begins with analysis of flow field and ends by searching of flutter critical point is presented .In this paper, flow parameters of the wing with high angle of attack are calculated by the theory of shock wave and expansion wave; the engineering arithmetic of aerodynamics heating based on reference enthalpy method is presented; unsteady aerodynamic force is calculated by the method of local flow piston theory. With the aerodynamics heating results as thermal load, the transient temperature field and mode of the wing are analyzed by the finite element analysis. Finally, flutter equations expressed by modal coordinates are founded by modal superposition method. This differential equation is reduced to differential equations set by state space method, and solved with integration by successive reductions in time domain. Aerodynamics heating, temperature field, mode and thermo-flutter of an engineering example are analyzed. These analysis show that： when Ma〉3, thermo-flutter critical dynamic pressure is obviously less than it in normal temperature, thermo-flutter critical dynamic pressure will decrease when mach number increases, so analysis of thermo-flutter is valuable when mach number is high.