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aeroelastic stability of full-span tiltrotor aircraft model in forward flight

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Chinese Journal of Aeronautics 2017年第6期30卷 1885-1894页

作者： Zhiquan LI Pinqi XIA College of Aerospace Engineering Nanjing University of Aeronautics and Astronautics Nanjing 210016 China

The existing full-span models of the tiltrotor aircraft adopted the rigid blade model without considering the coupling relationship among the elastic blade, wing and fuselage. To overcome the limitations of the existing full-span models and improve the precision of aeroelastic analysis of tiltrotor aircraft in forward flight, the aeroelastic stability analysis model of full-span tiltrotor aircraft in forward flight has been presented in this paper by considering the coupling among elastic blade, wing, fuselage and various components. The analytical model is validated by comparing with the calculation results and experimental data in the existing references. The influence of some structural parameters, such as the fuselage degrees of freedom, relative displacement between the hub center and the gravity center, and nacelle length, on the system stability is also investigated. The results show that the fuselage degrees of freedom decrease the critical stability velocity of tiltrotor aircraft, and the variation of the structural parameters has great influence on the system stability,and the instability form of system can change between the anti-symmetric and symmetric wing motions of vertical and chordwise bending.

关键词： aeroelastic stability Forward flight Full-span model Modal analysis Tiltrotor aircraft

Influence of structure parameters on aeroelastic stability for labyrinth seal based on energy method

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Propulsion and Power Research 2018年第4期7卷 288-295页

作者： Nengmao Wang Yanrong Wang Aimei Tian School of Energy and Power Engineering.Beihang University Beijing 100191China Collaborative Innovation Center for Advanced Aero-Engine Beijing 100191China School of Astronautics Beihang UniversityBeijing 100191China

Numerical analysis of turbomachinery based on energy method is used to predict the aeroelastic stability of the straight-through labyrinth seal by solving aerodynamic work and vibration modes has been ***'s found that the increase of pressure ratio leads to the in the circumferential direction of the labyrinth seal corresponds to the number of vibrating nodal *** order to investigate the influence of structure parameters,the effect of relative thickness of the tooth tip,the width of the seal cavity and the eccentricity of the rotor on the aeroelastic stability of the labyrinth seal has been *** result of numerical calculation shows that the change of the structural parameters can affect the aeroelastic stability of the labyrinth seal to a certain extent,and can be applied in the structural optimization.

关键词： Labyrinth seal aeroelastic stability Energy method Nodal diameters Structure parameters

MULTI-BODY aeroelastic stability ANALYSIS OF TILTROTOR AIRCRAFT IN HELICOPTER MODE

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维普期刊数据库

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Transactions of Nanjing University of Aeronautics and Astronautics 2006年第3期23卷 161-167页

作者：董凌华杨卫东夏品奇南京航空航天大学直升机旋翼动力学国家级重点实验室

The muhi-body analysis of the aeroelastic stability of the tiltrotor aircraft is presented. Muhi-body dynamic differential equations are combined with the equations of the unsteady dynamic inflow model to establish the complete unsteadily aeroelastic coupling analytical model of the tiltrotor. The stability of the tiltrotor in the helicopter mode is analyzed aiming at a semi span soft-inplane tihrotor model with an elastic wing. Parametric effects of the lag stiffness of blades and the flight speed are analyzed. Numerical simulations demonstrate that the multibody analytical model can analyze the aeroelastic stability of the tiltrotor aircraft in the helicopter mode.

关键词： tiltrotor helicopter aeroelastic stability multi body dynamics dynamic inflow

aeroelastic analysis and structural parametric design of composite rotor blade

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Chinese Journal of Aeronautics 2021年第1期34卷 336-349页

作者： Li MA Qijun ZHAO Kai ZHANG Xiayang ZHANG Mengmeng ZHAO National Key Laboratory of Science and Technology on Rotorcraft Aeromechanics Nanjing University of Aeronautics and AstronauticsNanjing 210016China

Based on FEM theory,a method of dynamic analysis for hingeless rotors considering anisotropic composite materials is established.A parametric modeling method of composite blade with typical profile and high simulation degree for design is *** the finite element method,the profile characteristics of rotor blade can be obtained efficiently and accurately,and the synchronization of parametric design and finite element analysis of structural characteristics can be *** a 23-degrees of freedom non-linear beam element is used to simulate the extended one-dimensional beam,thereby a nonlinear differential equation describing the elastic motion of the rotor is *** obtain the crosssectional target characteristics of the blades,an inverse design method is proposed for cross-section components based on combinatorial optimization *** calculation and validation work show that the proposed model can effectively analyze the aeroelastic characteristics of general composite ***,the influence of cross-sectional parameters on the aeroelastic stability and hub loads of hingeless rotor is analyzed and some remarkable conclusions are obtained.

关键词： aeroelastic stability Composite material Cross-section analysis Hub loads Inverse design Rotor

aeroelastic vibration analysis of a 1.5 stage compressor

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Propulsion and Power Research 2020年第1期9卷 26-36页

作者： Yun Zheng Qingzhe Gao Hui Yang Kang Xu School of Energy and Power Engineering Beihang UniversityBeijing100191China Collaborative Innovation Center for Advanced Aero-Engine Beijing100191China

aeroelastic vibration problems are commonly found in modern compressors operating in off-design *** amplitude vibration could lead to high cycle fatigue(HCF)of blade and usually occurs in front stages of axial *** this study,the influence of tip gap size on aeroelastic stability is analyzed in a 1.5 stage compressor with an in-house fluid-structure interaction code.A three-dimensional unstructured finite-volume compressible flow solver is applied in the fluid domain and a structure dynamic solver with the modal superimposition method for blade motion is used in the structure *** tip clearances of 1%,2%and 3%of tip axial chord at maximum rotor loading conditions at off-design speeds are analyzed for aeroelastic *** tip leakage flow and vortex structure can be seen near the blade tip region at a larger tip gap *** aeroelastic stability of rotor blade at different tip gap sizes is mainly influenced by the 1st torsion mode,and the variation of aerodynamic damping is not *** intensity of the tip vortex and shock wave are the key factors affecting the aeroelastic stability of rotor when tip gap size increases.

关键词： aeroelastic vibration problems Axial compressors Tip gap size aeroelastic stability Tip vortex Shock wave