Estimation of Aeroelastic Characteristics of Aerospace Planes in Increasing Speeds

本研究的目的是提出一种非定常预测方法，该方法估计稳定性（颤振或发散）边界和飞机模型的气动弹性特性，机翼对紊流的响应用阿尔马过程模拟。气动弹性特性和稳定性裕度的评估从AR系数的过程中确定的援助Akaike的AIC方法。稳定性边界通过在亚临界流量范围内评估的稳定性裕度的外推来估计。通过对低速和超音速风洞试验数据的应用，证实了本文方法的有效性，并对二维机翼模型在不可压缩湍流中的气动弹性响应进行了数值模拟，以阐明基于本文方法的估算的基本内容。仿真分析的一个重要确认是，从AR系数评估的稳定裕度的标准偏差迅速下降，作为流速接近稳定边界，不同于阻尼系数，这是在传统的方法中使用。这一事实为非平稳预报方法提供了重要依据，在该方法中，稳定边界是通过将稳定裕度的分散值画成一条直线作为包络线的上侧来确定的。

The objective of this study is to propose a nonstationary prediction method which estimates stability (flutter or divergence) boundaries and the aeroelastic characteristics of airplane models tested in an increasing, i.e., nonstationary flow.The response of the wings subjected to flow turbulence is modelled by an ARMA process. The aeroelastic characteristics and stability margin are evaluated from the AR coefficients of the process determined with the aid of Akaike's AIC approach. The stability boundary is estimated through extrapolation of the stability margin evaluated in a subcritical flow range. The effectiveness of the present estimation method has been confirmed through application to experimental data obtained in low-speed and supersonic wind-tunnel tests.In addition, numerical simulation of aeroelastic response of a two-dimensional wing model in an incompressible turbulent flow was performed in order to clarify fundamental aspects of estimation based on this estimation method. An important confirmation of the simulation analysis is that the standard deviation of the stability margin evaluated from the AR coefficients decreases rapidly as the flow speed approaches the stability boundary, unlike the damping coefficient which is used in conventional methods. This fact provides a significance basis for the nonstationary prediction method in which the stability boundary is determined by drawing a straight line as the upper side of an envelope for scattering values of the stability margin.