【作者】 董凌华；

【导师】 张呈林；

【作者基本信息】 南京航空航天大学 ， 飞行器设计， 2011， 博士

【摘要】 倾转旋翼机通过旋翼的倾转，实现在直升机飞行模式和飞机飞行模式之间动态转换，使其兼具直升机及固定翼飞机的飞行能力。倾转旋翼机的旋翼与机翼之间存在着严重的气弹耦合现象，尤其是旋翼倾转过渡飞行状态，系统的结构动力学特性、旋翼的气动力及入流均处于动态变化过程，具有复杂的非线性和非定常特性。本文通过理论分析与试验，重点研究倾转旋翼/机翼气弹耦合动力学特性。基于Hamilton原理，利用多体方法描述动力学部件的空间运动关系，充分考虑倾转旋翼/弹性机翼之间强耦合非线性的气动、惯性及结构耦合，建立了倾转旋翼/机翼气弹耦合动力学分析模型，所建立的模型保留了机翼弹性变形以及倾转角度速度与旋转旋翼之间的各种惯性耦合影响。旋翼入流采用带有动态尾迹弯曲修正的广义动态入流模型，综合考虑旋翼/机翼耦合变形，尤其是旋翼动态倾转过程中，响应、气动力及旋翼诱导速度之间的气动耦合影响。非线性的结构动力学模型与非定常的气动及入流模型集成为时域内紧耦合的气弹动力学综合分析模型，利用数值积分进行倾转旋翼机的瞬态响应分析。通过进行数值算例分析，结合带有复杂几何外形的等速万向铰倾转旋翼桨毂的模态试验、倾转旋翼/机翼气弹耦合动力学缩尺模型的风洞试验研究，开展了倾转旋翼/机翼气弹耦合动力学建模的验证研究。试验结果与模型计算分析结果吻合良好，试验研究与对比分析表明本文所建立的倾转旋翼/机翼气弹耦合动力学分析模型具有很高的分析精度，可以有效分析倾转旋翼/机翼耦合系统的气弹动力学问题。利用所建立的倾转旋翼/机翼气弹耦合动力学分析模型，进行了倾转旋翼机在倾转过渡状态的瞬态响应研究，并利用瞬态响应的方法进行了倾转旋翼机在飞机模式大速度前飞时的回转颤振机理研究。倾转过渡状态的瞬态响应分析研究了倾转操纵规律以及前飞速度对于旋翼/机翼气弹耦合响应的影响，最终进行了变旋翼转速变总距操纵的动态倾转过渡瞬态响应分析。回转颤振现象的瞬态响应研究从物理上描述了倾转旋翼的挥舞运动与机翼垂直弯曲及扭转模态发生不稳定气弹耦合的机理，并研究了复合材料机翼大梁气弹剪裁设计对于回转颤振抑制的有效性。基于所建立的倾转旋翼/机翼气弹耦合动力学分析模型，进行了倾转旋翼机的气弹稳定性参数影响研究，分析参数包括：机翼弹性、耦合刚度、机翼几何参数及复合材料的铺层设计参数；短舱惯量、倾转旋翼轴安装位置及长度；桨毂构型参数、挥舞变距调节等基本动力学设计参数。分析研究得到了一些有意义的结论与参数影响规律，这些结论可以用于指导倾转旋翼机的动力学设计。更多还原

【Abstract】 Tiltrotor aircraft can implement continuous flight conversion between helicopter mode andpropeller plane mode through the pivoting of rotor. Because the tiltrotor is planted at the tip of theelastic wing and the tiltrotor is permitted to flap, tiltrotor aircraft has seriously aeroelastical couplingsbetween rotor and wing. Especially in its conversion flight, inflows and aerodynamics of rotor and thedynamical characteristics of tiltrotor-wing coupled system are varied in dynamic process, which resultin complicated nonlinear and unsteady characteristics of tiltrotor-wing coupled system. This papergives emphasis to the researches on the dynamical characteristics of tiltrotor-wing aeroelasticallycoupled system with analyses and experiments.Basing on Hamilton’s principle, a dynamical analysis model of semi-span tiltrotor aircraft isdeveloped by the multi-body method with considerations of complex couplings between tiltrotor andwing due to the nonlinear and unsteady characteristics coming from the complicated aerodynamic andinertial force as well as the complicated structures. In which, all of nonlinearly inertial couplingsbetween the rotating blade and elastic distortions of wing are retained and variations of pivoting androtating speed of rotor are considered. Then, the generalized dynamic inflow model is used with themodification of dynamic wake distortion to wholly take into account the aeroelastical couplingsamong responses, aerodynamics and inflows for the coupled distortion of tiltrotor and wing,especially in conversion flight. Finally, all of the structural dynamic model, aerodynamic model andinflow model are tightly coupled together in time domain to analyze the response with implicatingnumeric integration method。The aeroelastically dynamic analysis model of tiltrotor-wing coupled system was validatedthrough numerical and experimental contrastive analyses. A modal experiment of gimbaled tiltrotorwith advanced geometry blade and aeroelastically dynamical experiments with reduced scale modelof semi-span tiltrotor have been completed in wind tunnel of LORA NUAA to support the validation.Contrastive analyses achieved good correlations between numerical and experimental results, whichindicate that the multi-body analytical model represented in this paper has capacities to analyzeaeroelastically dynamic characteristics of coupled tiltrotor-wing coupled system.The dynamic characteristics of tiltrotor aircraft in conversion flight and the mechanism of whirlflutter in prop-plane forward flight have been simulated by the method of transient responsecalculated with the validated analysis model. As to the conversion flight, effects of variations ofpivoting and rotating speed of rotor were analyzed first, and then, aeroelastic coupling responses oftiltrotor and wing during transition flight with varying rotational speed and varying pitch controls were simulated. The mechanism of whirl flutter simulated in transient response indicated that physicalphenomena of tiltrotor aircraft’s whirl flutter was the aeroelastic coupling radiation between the flapof tiltrotor and the vertical bending and torsion of elastic wing when flight velocity upon the boundaryspeed. Aiming at the mechanism of whirl flutter, the potential application of aeroelastically tailoringcomposite wing beam was analyzed.Aeroelastical stability of tiltrotor wing coupled system was analyzed with the analysis modeldeveloped in this research. The studied parameters included: the elastic and coupling stiffness of wing,structural geometry parameters of wing, the layer parameters of composite material of wingcrossbeam, the inertia of tilting nacelle, the length of hub to tilting hinge and the position of the tiltinghinge, structural parameters of hub and the coupling between flap and pitch. Some useful conclusionsand disciplines have been obtained which can be used to provide the guide to dynamic design oftiltrotor aircraft.更多还原