自由振荡风洞实验获取的随振幅变化的动导数的应用问题研究

Research on the flight-dynamic application problem of the dynamic stability derivative obtained from wind-tunnel free-oscillation experiment

本文研究了自由振荡风洞实验获取的动导数如何在飞行器动态特性分析、轨道仿真和飞行控制设计等飞行力学课题中应用的问题。讨论了将随振幅变化的动导数变换为随迎角变化的动导数的两种近似换算方法,提出了动导数换算的递推 辨识算法和多项式形式动导数的系数辨识算法。其中递推-辨识算法和多项式形式动导数的系数辨识算法都得到了令人满意的结果。

The dynamic stability derivative (DSD) obtained from wind-tunnel free-oscillation experiments (WTFOE) is usually as a function of amplitude, but it is more convenient in the analysis of aircraft dynamics, trajectory simulation, flight control design, and some more flight dynamic problems if the DSD is as a function of angle-of-attack. The problem, how to use the DSD obtained from WTFOE in these flight dynamic problems, is studied in this paper. Two approximate methods to transform the average dynamic stability derivative as a function of amplitude into the dynamic derivative as a function of angle-of-attack are discussed. A recurrence-identification algorithm for the dynamic stability derivative transformation and a coefficient identification algorithm for the derivative in the form of polynomial are developed, which provide satisfactory results.