共轴双旋翼直升机旋翼%2f机体耦合动稳定性分析.pdf

Nanjing University of Aeronautics and AstronauticsThe Graduate SchoolCollege of Aerospace EngineeringInvestigationof Coupled Rotor/Airframe Coaxial Helicopter Dynamic Stability A Thesis inFlight Vehicle DesignbyLV ZengsuiAdvised byProf. WANGHuamingSubmitted in Partial Fulfillmentof the Requirementsfor the Degree ofMaster of EngineeringDecember, 2014万方数据承诺书本人声明所呈交的硕士学位论文是本人在导师指导下进行的研究工作及取得的研究成果。除了文中特别加以标注和致谢的地方外,论文中不包含其他人已经发表或撰写过的研究成果,也不包含为获得南京航空航天大学或其他教育机构的学位或证书而使用过的材料。本人授权南京航空航天大学可以将学位论文的全部或部分内容编入有关数据库进行检索,可以采用影印、缩印或扫描等复制手段保存、汇编学位论文。(保密的学位论文在解密后适用本承诺书)作者签名:日期:万方数据南京航空航天大学硕士学位论文I摘要本文研究了共轴双旋翼直升机在地面工作时的旋翼/机体耦合系统的动稳定性。首先建立了共轴式直升机旋翼/机体耦合系统动力学分析模型,其中旋翼模型采用根部加弹簧的刚性桨叶,考虑桨叶挥舞和摆振自由度,采用气动干扰因子描述上下旋翼的气动干扰,桨盘处诱导速度采用均匀入流模型;机体模型中考虑横向、纵向平移及俯仰、滚转4个自由度,用牛顿法推导该分析模型的动力学方程组,并利用小扰动假设对其进行线化处理,得到系统的扰动运动方程。然后通过特征值计算,对共轴式直升机旋翼/机体耦合系统的固有特性及动稳定性进行分析,并给定摆振运动的角度作为初始条件,分析系统各模态的时域响应特性。最后利用机械动力学仿真软件Adams对共轴式直升机旋翼/机体耦合动稳定性进行验证分析,在Adams/View中建立参数相同的共轴式直升机模型,对系统动不稳定的转速范围以及上下旋翼高度差对系统动稳定性的影响进行研究,得到的结论与本文建立的理论模型分析结论基本吻合,验证了理论建模的有效性和计算的准确性。本文的研究表明,上旋翼的摆振后退型与机体滚转模态的耦合是主要的动不稳定源,下旋翼的存在会加剧系统的动不稳定性。对共轴式直升机的系统动稳定性产生的影响因素包括起落架刚度、上下旋翼高度差、机体质量等参数。本文的分析为共轴式直升机旋翼/机体耦合系统动力学设计提供理论指导。关键词:直升机,共轴双旋翼,动稳定性,旋翼/机体耦合,参数分析万方数据共轴双旋翼直升机旋翼/机体耦合动稳定性分析IIAbstractThe intention of this paper is to investigatethe rotor/fuselage coupled dynamic stability of coaxial helicopter working on the ground. Firstly, the rotor/fuselage coupled dynamic analytical model was established, the rigid blade with root spring of the rotor model is of flap and lag degree of freedom, aerodynamicinterferencefactor was induced to describe the interference of upper and lower rotor, thedisc induced velocity was modeled by uniform inflow. The fuselage model is of lateral, longitudinal, pitch and roll degree of freedom, governingequation sets of the model was deduced by Newton method, and linearized basedon the hypothesis of small disturbance then the perturbationequations were obtained. Secondly, the analysis of rotor/