【作者】 崔瑛；

【导师】 高正；

【作者基本信息】 南京航空航天大学 ， 飞行器设计， 2005， 硕士

【摘要】 直升机吊挂飞行机外运输,是其主要用途之一,在军事、民用领域中的应用均十分广泛。直升机吊挂飞行,与直升机非吊挂飞行状态相比,增加了新的气动载荷、重力载荷,和因此产生的对直升机重心的力矩,其飞行运动模式、低频振荡固有频率均发生改变。本文着重研究了吊挂物在飞行过程中的运动数学模型,及直升机/吊挂物整个系统的数学模型的建立。根据对直升机、吊挂物运动学特性的分析,利用牛顿定律建立模型。模型由包括吊挂物在内的多个部分组成,以机体运动为主运动方程,吊挂物运动为辅助方程,考虑到各部分之间的耦合,为非线性数学方程组。根据小扰动假定,对数学模型线性化,得到线性方程组、稳定性导数矩阵,进而分析整个系统的稳定特性。直升机机外吊挂飞行过程中,体现飞行品质的运动模态主要为荷兰滚模态、纵向浮沉振荡模态,以及吊挂物横向、纵向振荡模态。根据美国航空设计标准军用旋翼飞行器驾驶品质要求(ADS-33E-PRF)的相关条例,对直升机吊挂飞行进行飞行品质稳定性方面的评估。影响飞行品质稳定性要求的主要因素为:直升机飞行速度、吊挂物/直升机质量比、吊挂物气动特性、吊挂钢索长度等。通过对上述结构参数、性能参数的调节,可确定合理、经济的飞行参数,保证安全、高效的完成直升机机外吊挂飞行运输任务。更多还原

【Abstract】 The slung-load flight is one of the main uses of helicopter in both military and civilization domain. Compared with non-slung-load flight, additional aerodynamic load, gravity load should be considered in the slung-load system. So the moment to the gravity center, flight mode and the natural frequency will change.This paper specially studied the math modeling of the slung-load in flight, and the math model of the whole helicopter/slung-load system as well. First, the fuselage nonlinear dynamic equations are built, and then the slung-load dynamic equations. Small perturbation assumption was applied to linerarize the nonlinear equations at some trim points, then the stability of the system can be decided through eigen values analysis. During helicopter slung-load flight, the main flight quality modes include: phugoid, Dutch roll, longitude and latitude slung-load oscillation. According to the ADS-33E-PRF specifications, the flight stability qualities had been evaluated. The main factors which affected the flight stability quality included: forward flight speed, slung-load and helicopter mass ration, slung-load aerodynamic forces and cable length, etc. Through adjusting the above structure and performance parameters, rational flight parameters can be decided, which can ensure the safe helicopter mission operations of the slung-load flight.更多还原