APU飞机级控制系统设计研究

为充分发挥APU（辅助动力装置）在民用飞机上的作用,设计一个好的APU控制系统显得尤为重要。对APU飞机级控制系统的设计进行了相关研究,论述了APU控制板、APU控制器供电、燃油控制、应急停车、APU引气、起动／发电、风门控制和指示告警等控制子系统在设计时所要考虑的因素,并给出了相应的设计样例,然后从功能实现和电气原理的角度进行了详细地分析,可为APU飞机级控制系统的方案设计提供参考。     

试飞数据处理方法——升力曲线和极曲线

介绍了一种试飞数据处理的方法,详细介绍了数据处理步骤。并以具体的试飞数据为例,根据提供的方法得出升力系数和阻力系数,进而可得到升力曲线和极曲线。对比了试飞数据和风洞试验的结果,两者基本相一致。在处理大量试飞数据的过程中,编写了相应的程序,提高了工作效率。     

Orbital rendezvous mission planning using mixed integer nonlinear programming

The rendezvous and docking mission is usually divided into several phases, and the mission planning is performed phase by phase. A new planning method using mixed integer nonlinear programming, which investigates single phase parameters and phase connecting parameters simultaneously, is proposed to improve the rendezvous mission’s overall performance. The design variables are composed of integers and continuous-valued numbers. The integer part consists of the parameters for station-keeping and sensor-switching, the number of maneuvers in each rendezvous phase and the number of repeating periods to start the rendezvous mission. The continuous part consists of the orbital transfer time and the station-keeping duration. The objective function is a combination of the propellant consumed, the sun angle which represents the power available, and the terminal precision of each rendezvous phase. The operational requirements for the spacecraft–ground communication, sun illumination and the sensor transition are considered. The simple genetic algorithm, which is a combination of the integer-coded and real-coded genetic algorithm, is chosen to obtain the optimal solution. A practical rendezvous mission planning problem is solved by the proposed method. The results show that the method proposed can solve the integral rendezvous mission planning problem effectively, and the solution obtained can satisfy the operational constraints and has a good overall performance.     

星载电子设备元器件随机振动疲劳分析

星载电子设备通常要经历各种振动环境,在恶劣的随机振动环境中,设备中的元器件管脚及焊点容易出现疲劳问题。文章应用Miner疲劳损伤累积理论及三带宽技术,提出了一种实用有效的分析元器件管脚及焊点进行随机振动疲劳寿命的方法。     

导热增强型相变材料温控试验

为满足高超声速飞行器舱内温度要求,提出了在舵轴热短路区域使用相变材料进行热耗散的方案.通过开展导热增强型相变材料温控试验,获得了不同试验方案对舵轴及周围金属壳体的降温效果.结果表明,导热增强型相变材料由于良好的导热性能,能够很好地发挥相变吸热能力,对降低舵轴热短路区域的局部高温具有显著效果;金属壳体内、外同时使用低温和中温相变装置,能够将舵轴周围金属壳体温度控制在允许工作温度范围内(150℃).本研究可为飞行器舵轴温控设计提供指导.     

Nb-Si 基超高温合金的研究进展

Nb-Si基超高温合金由于熔点高、密度低和优良的高温强度等特点受到广泛关注,极具作为下一代高推重比航空发动机和超然冲压发动机的热端部件用材料的潜力.本文主要介绍了国内外在合金化、粉末冶金、定向凝固和热处理工艺对Nb-Si基合金组织和性能影响等方面的研究现状,并展望了其发展趋势.     

POE-g-MAH 对PA66 共混体系性能的影响

讨论了POE-g-MAH含量、MAH接枝率对PA66/POE/POE-g-MAH共混物性能的影响.当POE-g-MAH含量为10wt％～15wt％时,PA66/POE-g-MAH共混物发生脆-韧转变;随POE-g-MAH含量增加,共混物的缺口冲击强度、断裂伸长率显著增大,拉伸强度、弯曲强度、弯曲模量、熔体流动速率、吸水率均明显下降.当POE-g-MAH接枝率为0.05wt％～0.2wt％时,PA66/POE/POE-g-MAH共混物发生脆-韧转变;随POE-g-MAH接枝率增加,共混物的缺口冲击强度、断裂伸长率增大,拉伸强度、弯曲强度、弯曲模量、吸水率变化不大,熔体流动速率下降.SEM照片和Molau实验表明,POE-g-MAH对PA66具有显著的增容增韧效果.     

Microstructure and mechanical properties of hybrid fabricated 1Cr12Ni2WMoVNb steel by laser melting deposition

 Laser melting deposition was carried out to deposit a 1Cr12Ni2WMoVNb steel bar on a wrought bar of same material. Room-temperature tensile properties of the hybrid fabricated 1Cr12Ni2WMoVNb steel sample were evaluated, and microstructure, fracture surface morphology, and hardness profile were analyzed by an optical microscope (OM), a scanning electron microscope (SEM), and a hardness tester. Results show that the hybrid fabricated 1Cr12Ni2WMoVNb steel sample consists of laser deposited zone, wrought substrate zone, and heat affected zone (HAZ) of the wrought substrate. The laser deposited zone has coarse columnar prior austenite grains and fine well-aligned dendritic structure, while the HAZ of the wrought substrate has equiaxed prior austenite grains which are notably finer than those in the wrought substrate zone. Besides, austenitic transformation mechanism of the HAZ of the wrought substrate is different from that of the laser deposited zone during the reheating period of the laser deposition, which determines the different prior austenite grain morphologies of the two zones. Microhardness values of both the laser deposited zone and the HAZ of the wrought substrate are higher than that of the wrought substrate zone. Tensile properties of the hybrid fabricated 1Cr12Ni2WMoVNb steel sample are comparable to those of the wrought bar, and fracture occurs in the wrought substrate zone during the tensile test.     

一种极化敏感反射器用的展开机构

极化敏感反射器用的展开机构由一对相同的展开铰链及一个调速器组成，每个铰链都有提供动力的扭转弹簧及闭锁装置；调速器通过一个绳轮和展开轴连接。调速器中以１６４倍于展开轴转速旋转的离心盘提出阻尼力矩，以稳定展开速度，防止冲击过大，并保证较高的展开重精度。机构通过了包括振动，真空热循环等鉴定试验。在真空中高温５２．３℃下的展开速度比－２０℃下高１４％，常温常压下在模拟零重力试验设备上测得的展开重复精度优于