某运输机纵向周期模态频域仿真分析

在当代飞机设计及背景预研项目中,飞机纵向模态特性分析是必不可少的一个环节,模态特性也是影响飞机飞行操纵品质和飞行安全的因素之一,为了全面熟悉纵向周期模态特性,需要建立合理的纵向小扰动简化运动方程及相关动力学模型。给出了简化处理的线化小扰动方程,然后基于某运输机模型的气动数据以及飞行包线内的巡航状态,结合简化模型,在频域内对纵向周期模态特性进行了仿真分析。结果表明:简化模型可以准确地反映运输类飞机的纵向周期模态特性。同时,考虑了飞机发动机、操纵等结构系统对其模态特性的影响,因而提出了一些运输机设计和控制方法,为其它飞机型号设计提供工程理论指导。

Analysis of Frequency Domain Simulation with Longitudinal Period Mode for Transport Aircraft

The aircraft longitudinal period modes characteristics(LPMC) analysis is an indispensable step in modern aircraft design and background pre-research program,it is also the one of factors which influences flight quality and safety.In order to comprehensively study LPMC,the reasonable longitudinal low disturbed equations of motion(LDEM) and relative dynamical models need to be established.Its approximation with linearization and Cruise state in flight envelop were given,the simulation analysis in frequency domain was presented based on aerodynamical data combining with simplified model for aircraft,the model elementary validation was developed.It is demonstrated that model approximation can accurately reflect longitudinal short-period mode characteristics.At the same time,the influence of engine and control structure system on LPMC is considered,therefore,the design and control approaches are presented,this will provide engineer theory guidance for other aircraft design.