液氧煤油发动机地面试车故障监控系统研制

为了降低试车中发动机故障对产品和试车台造成的危害,提高安全性,设计了液氧煤油高压补燃发动机地面试车故障监控系统。主要介绍了系统总体实施方案、检测算法及验证情况。多次实际热试车考核和对大量热试车数据的验证表明,该系统未出现一次误报警,能够比指挥员提前检测到故障,系统简单可靠,易于实现,经济性好,对实现地面试车、箭载发动机故障检测和报警具有工程应用价值。     

我国大推力补燃氢氧发动机研究进展

氢氧火箭发动机因具有很高的性能,在国内外运载火箭中得到了广泛应用。为了更好地开展深空探测,必须研制大推力氢氧火箭发动机。本文综合分析了国内外氢氧发动机的发展历史和现状,简要介绍了我国220 t补燃循环氢氧发动机方案和关键技术研制进展,该技术方案先进。通过开展试验件冷态试验和缩尺组件热试验等,研究了核心部组件的关键技术和方案选型。开展全尺寸预燃室热试验等分系统热试验,研究组件级技术,初步突破了部分关键技术。建议加快开展大推力氢氧发动机工程研制,促进我国航天推进技术发展。     

Relationship of the diffuse aurora and SAR arc dynamics to substorms and storms

Investigation results of a diffuse aurora (DA) and stable auroral red (SAR) arc dynamics based on spectrophotometric observations at the Yakutsk meridian (199°E geomagnetic longitude) are presented. The relationship of an equatorward extension of DA in the 557.7 nm emission to a substorm growth phase during the magnetospheric convection intensification after the turn of IMF B_Z to the south is shown. The formation of SAR arc during the substorm expansion phase is investigated. The association of SAR arc dynamics with the development of asymmetric ring current (substorm injection) during the main phase of a storm is analyzed. It is shown how the pulsating precipitations of energetic ring current particles develop in the outer plasmasphere based on photometric observations.     

液体火箭发动机泵动态特性水力试验研究

为了获取新一代大型运载火箭POGO稳定性分析及液体火箭发动机动力学研究等所必需的发动机泵动力学传递函数,进行了以常温水为试验介质、全尺寸降转速液氧/煤油补燃循环发动机氧泵的动态特性水力试验,对试验原理、试验模拟准则、隔离贮箱设计、激励系统设计、控制和测量分析系统设计、试验内容及数据分析方法等进行了深入探讨。通过试验成功地识别出泵的POGO动特性参数及参数的规律特点,为其他水力试验和真实介质试验储备经验。     

Study of magnetic flux emergence and related activity in active region NOAA 10314

We study the extremely complex active region (AR) NOAA 10314, that was observed from March 13–19, 2003. This AR was the source of several energetic events, among them two major (X class) flares, along a few days. We follow the evolution of this AR since the very first stages of its emergence. From the photospheric evolution of the magnetic polarities observed with SOHO/MDI we infer the morphology of the flux tube that originates the AR. Using a computation technique that combines Local Correlation Tracking with magnetic induction constrains, we compute the rate of magnetic helicity injection at the photosphere during the observed evolution. From our results we conclude that the AR originated by the emergence of a severely deformed magnetic flux tube having a dominantly positive magnetic helicity.     

有迎角旋转钝锥的烧蚀滞后滚转力矩的算法

有迎角的再入旋转钝锥由于周向烧蚀滞后将产生滚转力矩。在烧蚀滞后滚转力矩的计算方法中。本文主要介绍滞后引射率和粗糙度对壁面磨擦系数联合影响的一种快速计算方法。给出计算结果与实验数据的比较，分析烧蚀滞后滚转力矩的模数随飞行参数的变化。     

Graph-tree-based software control flow checking for COTS processors on pico-satellites

 This paper proposes a generic high-performance and low-time-overhead software control flow checking solution, graph-tree-based control flow checking (GTCFC) for space-borne commercial- off-the-shelf (COTS) processors. A graph tree data structure with a topology similar to common trees is introduced to transform the control flow graphs of target programs. This together with design of IDs and signatures of its vertices and edges allows for an easy check of legality of actual branching during target program execution. As a result, the algorithm not only is capable of detecting all single and multiple branching errors with low latency and time overheads along with a linear-complexity space overhead, but also remains generic among arbitrary instruction sets and independent of any specific hardware. Tests of the algorithm using a COTS-processor-based onboard computer (OBC) of in-service ZDPS-1A pico-satellite products show that GTCFC can detect over 90% of the randomly injected and all-pattern-covering branching errors for different types of target programs, with performance and overheads consistent with the theoretical analysis; and beats well-established preeminent control flow checking algorithms in these dimensions. Furthermore, it is validated that GTCGC not only can be accommodated in pico-satellites conveniently with still sufficient system margins left, but also has the ability to minimize the risk of control flow errors being undetected in their space missions. Therefore, due to its effectiveness, efficiency, and compatibility, the GTCFC solution is ready for applications on COTS processors on pico-satellites in their real space missions.     

综合通信导航识别系统的故障注入方法研究

针对综合通信导航识别系统的综合化、模块化特点，在综合分析系统故障检测诊断机制、构建系统故障信息库的基础上，设计了一种面向综合通信导航识别系统的软件故障注入方案，可提高综合通信导航识别系统故障诊断软件的效能。通过利用此方案进行故障注入试验，验证了综合通信导航识别系统故障诊断软件的功能和性能。     

大涵道比涡扇发动机射流控制反推模型数值模拟

基于CFD(计算流体动力学)数值模拟技术,分别对两个不同涵道比涡扇发动机叶栅式射流控制反推模型进行计算,分析了反推力的产生及控制机理,并详细分析了二次流喷射压比、喷射位置、喷射角度及主流压比对流场结构和反推性能的影响.采用与反推力成正比的参数反推质量流量比来衡量反推性能的优劣,计算结果表明:二次流喷射压力、喷射位置和喷射角度是影响反推性能的重要参数,并且在一定的风扇涵道流前提下,存在最佳的二次流喷射位置、喷射角度和喷射压力;由于二次流引气量的限定,限制了二次流射入深度,因此射流控制反推技术不能用于超大涵道比发动机.      

多点喷射模型燃烧室性能CFD分析

采用Fluent的雷诺应力模型、非预混燃烧和非预混平衡化学反应PDF模型、压力-旋流雾化喷嘴模型、P1辐射模型,对多点喷射模型燃烧室的燃烧性能进行了计算。分析了不同余气系数的影响及旋流器下游各截面的温度分布,结果表明,数值计算能够模拟大部分流场结构,余气系数对回流区几乎没有影响,但对主燃区的峰值温度位置有明显作用;对NOx分布规律进行了研究,结果表明,NO的分布与温度分布类似,高温区对应高NO质量分数区;随着流动向下游发展,NO分布趋于均匀。