赛斯纳172R飞机着陆滑行停车故障研究

针对赛斯纳172R 飞机多次发生着陆滑行停车故障，对燃调系统结构和原理进行研究，分析了不当的维护检查工作、错误的操纵方法以及维护与操纵相互影响对燃调工作特性的影响，提出了针对性的维护、使用要求，可以有效避免该类故障的再次发生。     

雨水对飞机发动机的影响

雨水对飞机发动机影响较大,当飞机在大雨中降落时,可能会引发发动机熄火,但在飞机起飞时,能起到喷水加力的效应.为了对发动机防吞雨水停车和喷水增大推力研究提供参考,综述了CFM56-3型发动机投入使用后出现的一些吞雨停车故障,并总结了在发动机设计中采取的尽量减少雨水流入内涵的4点措施,介绍了喷水增大推力的机理和其在一些军、民用飞机发动机上的应用情况.     

起动-发电机“放电”所造成的PT6A-67R发动机空中停车故障分析

澳大利亚航空公司对Shrt SD360-300飞机发动机所发生的空中停车故障进行了分析,认为该故障是由起动-发电机放电导致该发动机1号轴承损坏造成的;采取了有效的排故措施.     

星上大功率电缆发热对热设计的影响分析

在目前的整星热设计中,通常不考虑电缆发热的影响,但随着设计实践的深入,发现在一些特定场合下,电缆发热对设计结果的影响十分明显,有时甚至是决定性的。文章以“海洋二号”卫星某大功率电缆为例,通过电缆所在舱段内设备温度计算结果与在轨实测数据的对比,分析了电缆发热对其所在舱段热设计结果的影响。并以此为基础,研究了电缆发热量与其带来的设计偏差之间的关系,提出了热设计中估算电缆发热对设备温度影响的方法,以及热设计中能否忽略电缆发热影响的判据。     

电推进羽流与航天器相互作用的研究现状与建议

电推进与传统的化学推进相比可以节约大量推进剂质量,被广泛用作地球同步轨道卫星南北位置保持和深空探测等任务的主推进系统。电推进器工作时产生的羽流与传统的化学推进器羽流有显著区别,电推进羽流对航天器的影响是进行卫星电推进器系统设计时需要重点关注的问题。文章讨论了电推进羽流对航天器的主要影响,介绍了国外在地面模拟试验、空间飞行验证和软件仿真技术等方面的研究现状,同时对国内开展羽流与航天器相互作用研究提出了建议。     

Z11直升机自转着陆试飞

通过对Z11直升机自转特性及自转着陆的试飞，研究了在自转着陆的进场着陆阶段，如何使旋翼能够提供最大的拉力，减小下降率，使直升机以低于起落架设计允许的最大下降率进行自转着陆，从而保证直 同和驾驶员的安全。最后分析探讨了Z11直升机空中停车后处置的驾驶技术及操纵要领。可供有关研究人员和直升机飞行员参考。     

某型大涵道比涡扇发动机飞行推力确定方法研究

以某型大涵道比涡扇发动机为研究对象,结合动力装置适航取证＂飞行推力确定＂试验科目,对该型发动机飞行推力确定方法进行了分析,并开发了该型发动机飞行推力确定计算分析软件。结合发动机设计单位给出的设计值,对该计算方法进行了验证。结果表明,采用飞行推力确定计算方法得到的计算值与设计值间吻合程度较高。     

大失准角下MIMU空中快速对准技术

 为了提高微小型无人机空中的反应速度和作业精度,提出将基于模型误差预测的扩展卡尔曼滤波(MEP-EKF)方法应用在大失准角下微惯性测量单元(MIMU)的空中对准中,通过不同机动飞行策略的仿真结果,证实MEP-EKF算法不仅能够实时估计出系统的模型误差,而且将其与扩展卡尔曼滤波(EKF)和Unscented卡尔曼滤波(UKF)方法进行了仿真比较,结果表明MEP-EKF算法在方位误差角的估计上,取得了比EKF和UKF精度高的仿真结果,使得方位失准角由30°快速下降到1°左右,而且MEP-EKF所需时间仅是UKF的17%。     

In-flight testing of the injection of the LISA Pathfinder test mass into a geodesic

LISA Pathfinder is a technology demonstrator space mission, aimed at testing key technologies for detecting gravitational waves in space. The mission is the precursor of LISA, the first space gravitational waves observatory, whose launch is scheduled for 2034. The LISA Pathfinder scientific payload includes two gravitational reference sensors (GRSs), each one containing a test mass (TM), which is the sensing body of the experiment. A mission critical task is to set each TM into a pure geodesic motion, i.e. guaranteeing an extremely low acceleration noise in the sub-Hertz frequency bandwidth. The grabbing positioning and release mechanism (GPRM), responsible for the injection of the TM into a geodesic trajectory, was widely tested on ground, with the limitations imposed by the 1-g environment. The experiments showed that the mechanism, working in its nominal conditions, is capable of releasing the TM into free-fall fulfilling the very strict constraint imposed on the TM residual velocity, in order to allow its capture on behalf of the electrostatic actuation.However, the first in-flight releases produced unexpected residual velocity components, for both the TMs. Moreover, all the residual velocity components were greater than maximum value set by the requirements. The main suspect is that unexpected contacts took place between the TM and the surroundings bodies. As a consequence, ad hoc manual release procedures had to be adopted for the few following injections performed during the nominal mission. These procedures still resulted in non compliant TM states which were captured only after impacts. However, such procedures seem not practicable for LISA, both for the limited repeatability of the system and for the unmanageable time lag of the telemetry/telecommand signals (about 4400 s). For this reason, at the end of the mission, the GPRM was deeply tested in-flight, performing a large number of releases, according to different strategies. The tests were carried out in order to understand the unexpected dynamics and limit its effects on the final injection. Some risk mitigation maneuvers have been tested aimed at minimizing the vibration of the system at the release and improving the alignment between the mechanism and the TM. However, no overall optimal release strategy to be implemented in LISA could be found, because the two GPRMs behaved differently.     

某型航空发动机停车冒黑烟故障研究分析

针对某型发动机在外场使用中多次出现停车后尾喷筒冒黑烟故障,进行故障原因分析、危害性分析,列出故障树,查清了故障原因并提出了改进措施,为解决同类发动机故障具有指导作用。