飞行器纵向非线性动力学建模对稳定性的影响

飞行器的稳定性分析与建立的动力学分析模型密切相关.传统的稳定性分析方法是基于小扰动假设建立线性化模型,当飞行状态中非线性特征明显时,其结果误差会带来多大的影响是人们关心的问题.通过建立飞行动力学非线性模型和气动力非线性模型,采用时间推进方法对两类非线性问题进行了比较系统的研究.数值计算结果表明,飞行动力学非线性模型与线性模型相比,周期增大、幅值减小、衰减率增大;而菲线性气动力模型对周期几乎没有影响,但对幅值有一定的影响.

Influence of longitudinal nonlinear dynamic model on stability of vehicle

Stability analysis of aircraft is closely related to the dynamics analysis model,the traditional stability analysis method is to establish a linear model based on small disturbance assumption.When the nonlinear characteristics are very obvious in a flight state,people often care about how much effects the errors between the calculated value and the true value will bring.On the basis of establishing nonlinear flight dynamics model and nonlinear aerodynamic model,this paper uses the time marching method to study two nonlinear problems systematically.The results show that the cycle increases,the amplitude decreases and the attenuation increases when the model of nonlinear flight dynamics equation is compared with linear model.The results also show that the nonlinear aerodynamic force has no effect on the cycle,but a certain influence on amplitude.