美国航空推进系统关键技术

在美国的国防关键技术计划中，航空推进技术受到重视。通过对美国国家级计划－－高性能涡轮发动机综合技术计划、脉冲式爆震波产生推力的新概念发动机计划、燃烧室内气流过渡为超声速的冲压发动机计划的研究，对美国选择推进系统的理由作了分析，并对各国在航空推进系统的研究和发展工作进行了评估。可以看出，日本、德国继美、英、法、俄后在航空航天的推进系统方面已完成了一系列的研究。日本斥巨资建立发动机模拟高空试验台。最后详细列出了燃气涡轮发动机，其它航空动力和燃料三类中的10项关键技术。     

应用 TVD 格式求解 N-S 方程预测透平叶栅二次流损失

应用ＴＶＤ格式和Ｂａｌｄｗｉｎ－Ｌｏｍａｘ代数紊流模型求解三维Ｎ－Ｓ方程,详细模拟出了一个直列透平叶栅中二次流及其损失在叶栅通道中的产生和发展过程,并给出了叶栅损失的分布状况,其结果深刻揭示了透平叶栅二次流损失的产生发展机制。本文计算得到的叶栅损失的栅距平均值沿叶高的分布曲线与实验值吻合良好,表明格式求解精度较高。     

胶焊接头中焊点大小对应力分布的影响

采用三维弹塑性有限元数值分析方法,研究了采用弹性模量较高的酚醛树脂和弹性模量较低的丙烯酸酯胶粘剂的胶焊接头中,焊点直径对应力分布的影响。     

流动稳定性中小扰动波传播速度的数值研究

在保守系统中，小扰动波如线性水波及线性重力内波等均以其群速度传播，且群速度等于能流速度，在非保守系统中，波的传播速度还是个不十分清楚的问题。本文用数值计算的方法研究流动稳定性问题中小扰动波的传播速度，结果表明，波的传播速度并不等于能流速度，而与复群速度的实部近似相等。本文还用一简单的模型对此给予了解释。     

THE ELECTRON DRIFT INSTRUMENT FOR CLUSTER

The Electron Drift Instrument (EDI) measures the drift of a weak beam of test electrons that, when emitted in certain directions, return to the spacecraft after one or more gyrations. This drift is related to the electric field and the gradient in the magnetic field, and these quantities can, by use of different electron energies, be determined separately. As a by-product, the magnetic field strength is also measured. The present paper describes the scientific objectives, the experimental method, and the technical realization of the various elements of the instrument.     

毕业设计成绩采用计算机评分的尝试

本文介绍发计算机评分的具体实施办法，并给出了评分过程的流程图和评分的软件，最后论述了评分办法的可行性。     

The Toroidal Imaging Mass-Angle Spectrograph (TIMAS) for the polar mission

The science objectives of the Toroidal Imaging Mass-Angle Spectrograph (TIMAS) are to investigate the transfer of solar wind energy and momentum to the magnetosphere, the interaction between the magnetosphere and the ionosphere, the transport processes that distribute plasma and energy throughout the magnetosphere, and the interactions that occur as plasma of different origins and histories mix and interact. In order to meet these objectives the TIMAS instrument measures virtually the full three-dimensional velocity distribution functions of all major magnetospheric ion species with one-half spin period time resolution. The TIMAS is a first-order double focusing (angle and energy), imaging spectrograph that simultaneously measures all mass per charge components from 1 AMU e^–1 to greater than 32 AMU e^–1 over a nearly 360° by 10° instantaneous field-of-view. Mass per charge is dispersed radially on an annular microchannel plate detector and the azimuthal position on the detector is a map of the instantaneous 360° field of view. With the rotation of the spacecraft, the TIMAS sweeps out very nearly a 4 solid angle image in a half spin period. The energy per charge range from 15 eV e^–1 to 32 keV e^–1 is covered in 28 non-contiguous steps spaced approximately logarithmically with adjacent steps separated by about 30%. Each energy step is sampled for approximately 20 ms;14 step (odd or even) energy sweeps are completed 16 times per spin. In order to handle the large volume of data within the telemetry limitations the distributions are compressed to varying degrees in angle and energy, log-count compressed and then further compressed by a lossless technique. This data processing task is supported by two SA3300 microprocessors. The voltages (up to 5 kV) for the tandem toroidal electrostatic analyzers and preacceleration sections are supplied from fixed high voltage supplies using optically controlled series-shunt regulators.     

圆弧腔内有气膜孔的多排射流冲击传热试验研究

在燃气涡轮叶片中,常常在内腔采用冷空气射流冲击热壁,和把冷空气从气膜小孔排往叶片外表面,形成冷气膜,冷却和保护叶片,以便提高燃气温度,改善发动机的性能。对于叶背内腔的多排射流冲击冷却,上游射流沿腔壁流动所形成的横流会影响到下游排孔的冲击射流;同时还具有受冲击的壁面是弧形的及沿弧腔一般存在气膜出气孔的特点。本文针对这两项因素进行了模拟试验,与新近获得的平直腔冲击传热试验结果作了比较。结果表明,这两项因素均有利于提高内部冷却效果。      

Dynamics of magnetospheric ion Composition as observed by the GEOS mass spectrometer

After one year of operation the GEOS-1 Ion Composition Experiment has surveyed plasma composition at all local times in the L range 3 8 and the energy per charge range from thermal to 16 keV/e. From measurements made in the keV range during eleven magnetic storms we find that the percentage of heavy (M/Q > 1) ions present in the outer magnetosphere increases by a factor of 3 to 10 during disturbances. We conclude that two independent sources (solar wind, characterized by ⁴He²⁺, and ionosphere, characterized by O⁺) give on the average comparable contributions to injected populations, although in a single event one or the other source may dominate. However, in magnetically quiet periods protons are the dominant species with a few percent of heavy ions. With the help of special satellite manoeuvres magnetic field aligned fluxes of 0.05-3 keV/e H⁺, He⁺, O⁺ with traces of O²⁺ have been observed which may be related to ion beams found previously at lower altitudes in the auroral zone. At still lower energies ( 1 eV/e) the thermal plasma population is found to be made up of six ion species, three of which, D⁺, He²⁺ and O²⁺, were unknown in the magnetosphere prior to the GEOS-1 measurements. We present here a study of the evolution of doubly charged ions and their parent populations over four consecutive days. Various production mechanisms for doubly charged ions are discussed. We argue that ionization of singly charged ions by UV and energetic electrons and protons is the dominant process for plasmasphere production. Furthermore, the observed high concentrations of O²⁺ at high altitudes are a result of production in the upper ionosphere and plasmasphere combined with upward transport by thermal diffusion. Throughout the 1 year lifetime of GEOS-1 the ICE functioned perfectly and, because of its novel design, a short review of technical performance is included here.