【摘要】 在分析五阶方程各模态特性的基础上,通过特征多项式根与系数的关系,证明了四阶方程动稳定不能确保五阶方程一定动稳定;同时通过四次与五次特征多项式的分析比较,给出四阶方程作为五阶方程有效近似的判定准则,作出判定曲线,得到四阶方程适用的飞高范围,并分析了各气动导数的变化对动稳定性的影响,为设计者提供必要的依据更多还原

【Abstract】 Based on discussion of the characteristics of each mode in the fifth order equation, by the relation between the roots and coefficients of the polynomials, this paper demonstrated that the dynamic stability deduced from the fourth order equation can not ensure that of the fifth order equation. By comparing the fourth order and the fifth order characteristic polynomials, the measure that the fourth equation is the valid approximation of the fifth order equation was given, from which the curves of valid approximation was drawn and the height scope of valid application of the fourth order equation was got. The influence of major aerodynamic derivatives on dynamic stability was discussed.更多还原