鲁棒匹配点颤振预测的高效μ方法
Efficient μ method in predicting robust match-point flutter
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摘要: 基于含有参数不确定性的时域鲁棒颤振μ预测工具, 首先提出一种不确定多项式建模方法, 该方法通过线性分式变换(LFT)最终可以得到较低阶次不确定描述; 然后, 考虑到参数不确定问题中实μ(realμ)的计算复杂性, 又提出一种包含二分法的鲁棒颤振预测技术, 该方法是基于在一定飞行范围内飞行速度与气弹系统稳定性间的简单关系, 它能够避免鲁棒匹配点颤振预测中包含的高阶速度摄动块, 从而大大提高颤振预测的计算效率. 最后数值验证和对比表明了该方法的高效性.Abstract: Based on the previous u-tool in predicting robustmatch-point flutter of the aeroelastic system with parametric uncertainties,this paper proposes a new modelling approach of uncertain polynomials. Theproper linear fractional transformation (LFT) is firstly applied to obtain amore reduced uncertain description. Furthermore, regarding the computationalcomplexity of real μ problem aroused from parametric uncertainties,another technique involving bisection method to predict the robust flutteris presented, which is based on the simple relationship between the flightspeed and stability of aeroelastic system in certain flight range. The μ method based on bisection search is very computational efficient throughnumerical validation and comparison, due to the avoidance of the high-ordervelocity perturbation block in previous robust match-point flutter model.