潜射导弹级间段密封圈动态密封性能模拟试验方法

根据潜射导弹级间段密封圈在出水过程中的动态变形参数设计了一套模拟试验件和加载、加水及测量装置,采用摆锤冲击加载方式和裂纹动态张开位移测量方法再现了密封圈在导弹出水过程中的使用条件,证明密封圈在规定的开缝宽度、开缝时间和弹体内外压差的使用环境下能够保证防水和密封效果。利用两自由度冲击响应模型分析了试验的动响应曲线,给出了试验系统模态参数的识别结果。     

台阶篦齿与衬套轴向位置和转速对封严特性影响的实验

设计了上台阶和下台阶篦齿两组实验模型,研究了旋转和静止两种状态下篦齿进出口压比、篦齿与衬套轴向相对位置以及转速对封严特性的影响.结果表明:齿型结构尺寸相同时,上台阶篦齿和下台阶篦齿的封严特性相似,增加篦齿前后腔压比,台阶篦齿的泄漏系数增加;进口总压和总温一定时,齿间压力沿流动方向线性下降;台阶篦齿与台阶衬套的轴向相对位置的改变对台阶篦齿的泄漏量影响不大;低转速时旋转速度对台阶篦齿泄漏影响也不大.      

封严篦齿结构特性的数值分析和实验研究

对发动机中封严篦齿进行了相关齿形的变化 ,建立了 8种封严结构模型 ,运用 RNG k～ ε湍流模型、非结构化网格和 SIMPLE算法来模拟封严篦齿流动问题。探讨了篦齿前后压比与泄漏系数的变化关系 ,系统分析了齿形结构的微小变化对封严效果的影响。筛选出一种齿形进行实验研究 ,计算与实验变化规律一致 ,误差为1 0 .87%。通过对篦齿模型不同倾角的数值模拟 ,发现当篦齿朝气流倾斜一定角度时 ,有利于封严 ,考虑工艺性以及封严效果的综合因素 ,倾角选择在 60°左右较为合理。研究结果表明 :齿腔大小和齿腔形状是决定篦齿封严效果的重要因素。     

固体发动机的密封问题

对固体火箭发动机密封的充分必要条件及密封界面上的应力分布进行了分析。为了提高密封的可靠性，对Ｏ形圈密封结构设计提出了若干建设性意见。     

1.5级涡轮前后轮缘密封封严流动特性研究

为了研究前后腔轮缘密封封严特性和封严出流与主流的交互作用,对转静叶片之间带有前后封严腔的1.5级涡轮进行了三维定常数值模拟,研究了不同封严流量下前后封严腔出口处流场分布并采用附加变量法对比分析了前后腔轮缘密封效率。结果表明：前封严腔主流燃气入侵位置主要受到来自上游导叶尾迹的影响,后封严腔主流燃气入侵位置主要受到下游导叶前缘位势场影响;封严出流影响了20%叶高以下的主流区域,增大了轮毂二次流强度;采用相同封严流量下时前封严腔的封严效率较后腔更低且有着更大的封严效率波动。     

径向密封设计及预紧力分析

主要描述了航天器结构设计中所采用的三种径向密封结构形式以及密封力的计算方法。在密封容器内压作用下,控制密封法兰两螺栓间的挠度变形,使两螺栓间法兰的间隙不大于0.1～0.2mm,从而达到满意的密封效果。同时,在密封实施过程中通过控制连接螺栓的拧紧力矩来确保密封法兰间的压紧力,通过紧固件的防松处理,提高法兰连接的可靠性。     

光刻技术在流体动力密封研究中的应用

主要介绍了流体动力密封螺旋槽动环光刻工艺的特点、原理、工艺过程、工艺流程、槽深控制方法以及应用情况，提出了采用高能束流刻蚀螺旋槽动环的新途径．结果表明，采用标准MEMS光刻工艺技术和化学铣切工艺技术，可加工出满足设计要求的螺旋槽动环．     

High-resolution simulation for rotorcraft aerodynamics in hovering and vertical descending flight using a hybrid method

A high-resolution simulation tool for rotorcraft aerodynamics is developed by coupling CFD with a Vorticity Transport Model (VTM). An Eulerian-based CFD module is used to model the blade near body flowfield, and a Lagrangian-based VTM module is employed for vortex tracking in the far wake. The coupling procedure is implemented by transmitting vortex sources to the VTM module and feeding boundary conditions back to the CFD module. The presented CFD/VTM hybrid solver is firstly validated by hover cases of three different rotor configurations. Simulation results, including the blade surface pressure distribution, rotor downwash, and hover figure of merit, exhibit favorable correlations with available experimental data. Then, a rotor operated in vertical descending flight with a fixed collective pitch is investigated. It is shown that the CFD/VTM coupling method is suitable for rotor wake simulation. Wake instabilities (far wake breakdown in hover and toroidal wake pattern in the vortex ring state) are successfully demonstrated with a moderate computational cost.     

简单实用的步进电机驱动电源

本文介绍了利用ＥＰＲＯＭ芯片构成步进电机的驱动电源，并对驱动电源及频率混同电路进行了分析和设计。     

Three-line structured light vision system for non-cooperative satellites in proximity operations

Adapter ring is a commonly used component in non-cooperative satellites, which has high strength and is suitable to be recognized and grasped by the space manipulator. During proximity operations, this circle feature may be occluded by the robot arm or limited field of view. Moreover, the captured images may be underexposed when there is not enough illumination. To address these problems, this paper presents a structured light vision system with three line lasers and a monocular camera. The lasers project lines onto the surface of the satellite, and six break points are formed along both sides of the adapter ring. A closed-form solution for real-time pose estimation is given using these break points. Then, a virtual structured light platform is constructed to simulate synthetic images of the target satellite. Compared with the predefined camera parameters and relative positions, the proposed method is demonstrated to be more effective, especially at a close distance. Besides, a physical space verification system is set up to prove the effectiveness and robustness of our method under different light conditions. Experimental results indicate that it is a practical and effective method for the pose measurement of on-orbit tasks.