具有反应流的固体冲压式火箭 发动机侧向进气道排放燃烧室的研究

固体冲压式火箭发动机是冲压发动机的一种变种。本研究使用一个带侧向空气道的排放燃烧室。考虑反应流,在燃气发生器中装填了50％高氯酸铵和50％聚酯的富燃推进剂。将κ—ε联立方程描述的湍流模型和一个简单、一步、快速反应的化学动力学总合成椭圆型偏微分方程来描述流场。为了适合所研究的问题,由改进的TEACH计算机程序来求解。基于此分析,更加深入地了解到混合和燃烧对固体冲压式火箭发动机全部性能的影响。将侧向空气进气道的位置移向燃料进气道,减少侧向空气进气道的角度,以及增加空气对燃料的比例,都能改善混合和燃烧特性,提高固体冲压式火箭发动机的比冲,这与Vanka的分析结果和Schadow的试验数据定性地一致。     

含硝酸酯增塑剂的固体推进剂的脆化研究

本文介绍硝酸酯增塑的聚醚聚氨酯推进剂在低温贮存中,解决失去应变能力(脆化)问题的研究结果。这种高度增塑的推进剂在低温下短期贮存,几乎完全失去了应变能力。研究这种脆化的原因表明,交联密度以及粘合剂配方是起作用的因素。湿度曾被考虑是因素之一,但实验证明并非如此。实验表明增塑剂结晶是脆变的主要原因但不一定与增塑剂的凝固点有关。重新测定某些增塑剂的凝固点是研究工作的一部份。放入增塑剂晶体增加了推进剂脆变速度。单独采用丁三醇三硝酸酯(BTTN)或是混合增塑剂可以解决这个问题。采用混合增塑剂可以得到最好的低温性能。     

机载雷达系统中的空—时自适应处理

本文概述了空—时自适应处理(STAP)在现代雷达系统中，尤其是在强干涉和人为干扰下的机载雷达系统中的应用情况。简要介绍处理方法后，叙述了STAP在导致非平稳信号环境的热杂波和非均匀雷达环境中STAP的应用结果。分析了在这种实际情况下采用STAP处理所存在的局限。结尾部分为使用圆形阵列所得到的一些STAP近期结果。     

Voluntary head stabilization in space during trunk movements in weightlessness

The ability to voluntarily stabilize the head in space during lateral rhythmic oscillations of the trunk has been investigated during parabolic flights. Five healthy young subjects, who gave informed consent, were examined. The movements were performed with eyes open or eyes closed, either during phases of microgravity or phases of normal gravity. The main result to emerge from this study is that the head may be stabilized in space about the roll axis under microgravity conditions with, as well as without vision, despite the reduction of the vestibular afferent and the muscle proprioceptive inputs. Moreover, the absence of head stabilization about the yaw axis confirms that the degrees of freedom of the neck can be independently controlled, as it was previously shown [1]. These results seem to indicate that voluntary head stabilization does not depend crucially upon static vestibular afferents. Head stabilization in space may be in fact organized on the basis of either dynamic vestibular afferents or a postural body scheme.     

航天发动机用的钛合金壳体

自从60年代初期以来,6Al—4V钛合金就被广泛地用于航天发动机壳体。本文描述了钛合金火箭发动机壳体(其最小极限抗拉强度的设计值达到175,000磅/英寸~2。)从锻件到加工成产品的工艺制造过程。对设计经验和该产品独特的工艺控制过程,如热处理和金相检验,也给予评论。本文对钛合金压力容器的优点,如多次使用、推力向量校准以及附加法兰和部件易于组合等,都作了介绍。     

The ankle ergometer: a new tool for quantifying changes in mechanical properties of human muscle as a result of spaceflight

A mechanical device for studying changes in mechanical properties of human muscle as a result of spaceflight is presented. Its main capacities are to allow during a given experiment investigation of both contractile and visco-elastic properties of a musculo-articular complex using respectively isometric contractions, isokinetic movements, quick-release tests and sinusoidal perturbations. This device is a motor driven ergometer associated to an experimental protocol designed for pre- and post-flight experiments. As microgravity preferentially affects postural muscles, the apparatus was designed to test muscle groups crossing the ankle joint. Three subjects were tested during the Euromir '94 mission. Preliminary results obtained on the european astronaut are briefly reported. During the next two years the experiments will be performed during six missions.     

New methods for microbial contamination monitoring: an experiment on board the MIR orbital station

Experiment T2, carried out during the Euromir'95 mission, was an important step toward innovative methods for spacecraft microbial contamination monitoring. A new standard sampling technique permitted samples to be analysed by different means. On board, two analysis methods were tested in parallel: Bioluminescence and Miniculture. In turn, downloaded samples are being analysed by polymerase chain reaction (PCR), a powerful and promising method for the rapid detection, identification and quantification of pathogens and biofouling agents in closed manned habitats.     

铁磁流体润滑的轴颈轴承研究

对一种铁磁流体润滑的三垫浅腔轴颈轴承进行了研究。轴承两端具有铁磁流体密封。三块瓦中有一块是可变形的弹性瓦。使用Reynolds方程和弹性瓦变形的关系式,得到了轴承的理论特性。对理论计算和实验结果作了比较,两者令人满意地符合。研究结果表明,铁磁流体轴承比普通滑动轴承具有一些优点。它们在运转中没有端泄和不需要任何供应系统,所以它们与滚动轴承一样地简单。可以变形的弹性瓦使得轴承具有更好的性能并且拓宽了它的工业应用。     

钝体入水时的水下声场的测量

对钝体入水时的水下声场进行了深入研究。在水中大约30个不同的测点上，测量了入水时产生的水中激波(声波)的压力，从而获得了激波的空间能量分布及其传播速度的实验数据。     

固体推进剂火箭发动机最大性能

目前,广泛地应用热化学模型预算发动机的最大性能,而且模型假定流场是一维的。然而,实验与计算表明,其内部流动可能具有显著的横向总压梯度,这将引起性能偏离一维流模型的计算结果。但在整体分析的范围内研究了这些影响。发现对有喷管的发动机是可以忽略的。