双转子轴间滑油颗粒运动轨迹参数化模型

为研究双转子轴间滑油颗粒运动对环下润滑收油效率及轴承腔油气分离效率的影响,建立了对转轴间在边界层流场结构下基于质点运动学的滑油颗粒运动轨迹参数化模型,并采用经实验验证的计算流体力学（CFD）数值计算结果进行验证。双转子轴间的边界层流场结构的确定运用了对湍流边界层卡门三层结构速度分布进行修正的方法。结果表明：给出的参数化模型可以很好地描述双转子轴间的滑油颗粒运动规律。直径较大的颗粒径直或沿弧线迅速到达外轴,而直径较小的颗粒中存在一个在给定停留时间内使颗粒无法到达外轴的最大直径,小于这一临界直径的颗粒在有轴向气流时将被吹离轴间环腔。     

涡轮泵转子的临界转速研究 (Ⅲ)计入液体作用力时涡轮泵转子的临界转速

给出了有液体作用时盘的传递矩阵,然后计算了三盘双支承同轴涡轮泵转子的临界转速,对计入和不计入液体作用时的频率谱和临界转速值作了比较,结果表明频率谱有质的区别,液体对泵轮的作用显著影响转子的临界转速值     

齿轮旋翼传动系统动态固有特性识别

通过对齿轮旋翼传动系统进行理论分析,在运转的条件下进行实验测定和在线识别,指出由于旋翼的非线性耦合作用,使得带有旋翼的齿轮传动系统具有不同于其它齿轮系统的特有特性,即动态特性随转速的不同而发生变化,并得到了其变化规律。     

低振动旋翼桨叶的动力学优化设计

从工程应用的角度，在桨叶气动外形参数和桨毂型式确定的情况下，探讨在设计阶段如何通过设计参数的选择设计桨叶使桨根切力最小，从而降低直升机相应的振动水平。研究了３种情况的桨叶设计：（１）控制桨叶的固有频率；（２）控制桨叶挥舞一阶振型节点位置；（３）振动水平指数最小。在分析比较的基础上给出了既能降低桨根切力减小直升机相应振动水平又能改善桨叶疲劳状况的桨叶动力学优化设计方法。     

轴向预紧端齿连接转子的动力特性分析

建立了用有限元子结构模态综合法进行轴向预紧端齿连接转子动力特性分析的公式系统。重点阐述如何考虑端齿及变轴力的影响, 如何获得变轴力端齿梁元的性质矩阵和建立变轴力端齿梁元及系统的运动方程。      

原理性电控旋翼系统试验研究

电控旋翼是于本世纪初提出的一种新概念旋翼系统。本文首次开展了电控旋翼的试验研究。首先自行研制了一套用于试验的原理性电控旋翼系统。以此为基础,进行了悬停和前飞状态下的电控旋翼襟翼总距和周期变距操纵试验。试验结果表明,电控旋翼的襟翼总距和周期变距操纵效果与常规旋翼类似,电控旋翼完全可以取代传统的自动倾斜器操纵系统实现旋翼操纵。理论与试验结果的对比则相互印证了正确性。     

直升机旋翼桨叶气弹优化减振设计方法

从振源着手通过设计参数的最优选择设计直升机旋翼桨叶,使传递到机身的交变载荷最小达到降低振动水平的目的是旋翼桨叶设计思想的进步。本文在简单概述该方法的基础上,以某4桨摆振柔软的无铰复合材料桨叶为研究对象,将其大梁模拟为一单闭室复合材料盒形梁,研究了通过铺层角的优化选择,降低4次/转的桨毂交变力与力矩的情况。数值算例表明方法效果良好。      

F-35 联合仿真环境(JSE)研究

美国空军F-35 联合仿真环境(JSE)旨在消除露天试验场的限制,通过仿真满足未来作战试验需求,但目前 JSE 开发严重滞后。通过分析洛克希德·马丁公司、美国空军与海军相关资料,明确了 JSE 分区域构建通过接口集成不同类型的服务。同时,JSE通过软件架构与硬件设施建设满足初始作战能力要求,其复杂性导致开发进度缓慢。虽多次延期影响了F-35的初始作战试验鉴定,但美军继续推进相关建设工作,以解决当前试验鉴定的局限性。JSE代表了未来装备作战试验训练的发展方向,值得借鉴。     

Interval analysis of rotor dynamic response based on Chebyshev polynomials

Uncertainty is extensively involved in the rotor systems of rotating machinery, which may cause an unstable vibrational response. To take the uncertainty into consideration for the uncertain rotor-bearing system, an improved unified interval analysis method based on the Chebyshev expansion is established in this paper. Firstly, the Chebyshev Interval Method (CIM) to calculate not only the critical speeds but also the dynamic response of rotor with uncertain parameters is introduced. Then, the numerical investigation is carried out based on the developed double disk rotor model and computation procedure, and the results demonstrate the validity. But when the uncertainty is sufficiently large to influence critical speeds, the upper and lower bounds are far from the actual bounds. In order to overcome the defects, a Bound Correction Interval analysis Method (BCIM) is proposed based on the Chebyshev expansion and the modal superposition. In use of the improved method, the bounds of the interval responses, especially the upper bound, are corrected, and the comparison with other methods demonstrates that the higher accuracy and a wider application range.     

Intrinsic physical relationships between rotor modal shapes and instantaneous vibrational energy flow transmission characteristics: Theoretical and numerical analysis and application

The modal vibration of the rotor is the main cause of excessive vibration of the aero-engine overall structure. To attenuate the vibration of the rotor under different modal shapes from the perspective of energy control, the intrinsic physical relationships between rotor modal shapes and instantaneous vibrational energy flow transmission characteristics is derived from the general equation of motion base on the structural intensity method. A dual-rotor-support-casing coupling model subjected to the rotor unbalanced forces is established by the finite element method in this paper. The transmission, conversion and balance relationships of the vibrational energy flow for the rotors in the first-order bending modal shape, the conical whirling modal shape and the translational modal shape are analyzed, respectively. The results show that the vibrational energy flow transmitted to the structure can be converted into the strain energy, the kinetic energy and the energy dissipated by the damping of the structure. The vibrational energy flow transmission characteristics of rotors with different modal shapes are quite different. Especially for the first-order bending modal shape, the vibrational energy flow and the strain energy are transmitted and converted to each other in the middle part of the rotor shaft, resulting in large deformation at this part. To attenuate this harmful vibration, the influences of grooving on the shaft on the first-order bending vibration are studied from the perspective of transmission control of vibrational energy flow. This study can provide theoretical references and guidance for the vibration attenuation of the rotors in different modal shapes from a more essential perspective.