预测AP/HTPB推进剂药浆粘度的经验模型

高固体含量推进剂药浆粘度的理论处理很困难,本文提出了预测AP/HTPB推进剂药浆粘度的经验模型,把药浆粘度跟体积分数C_1关联起来,得到如下方程:logηr=ao+∑a_iC_i+∑b_iC_i~2+Σc_iC_i~3再采用回归分析,求解出每个回归系数。借助该模型,可预测单级配、多级配AP/HTPB推进剂药浆粘度。使用布氏粘度计测定药浆粘度。同时研究了药浆粘度与固体含量、AP粒度比和混合比的关系。     

重新设计的航天飞机固体火箭助推器现场接头——锡奥科尔公司开始全尺寸试验

介绍了航天飞机固体助推器的一种新式现场接头设计,以及航天飞机恢复飞行前安排的各项必须试验。     

“阿里安”L5发动机的研制状况

“阿里安”L5是欧洲研制的最重要的中等推力级可贮存的二元推进剂发动机.它采用了多元件喷射器的设计原理,这种喷射器使用多个同轴喷射元件、一个燃料再生冷却燃烧室和一个辐射冷却的喷管扩展段.研制该发动机各部件所运用的技术与MBB-ERNO公司研制“阿里安”HM7液氧/液氢发动机时运用的技术相类似,但由于L5发动机的推进剂具有二元的基本特性,故现有的液氧/液氢技术只能部分采纳.对此MBB-ERNO公司提出了一项实验性计划来论证同轴式喷射器原理的可行性.L5发动机的研制工作包括整台发动机的设计及推进分系统的布局.叙述L5发动机的设计、性能和工作特性,以及研制状况,重点介绍目前正在研制的喷射器.     

高速通用遥测计算机系统的新体系结构

遥测计算机系统有如下一些重要的发展趋势:1.码速率更高。2.数据格式更复杂。3.硬件预处理与压缩。4.速度更快、适应性更强的通用计算机接口。5.32位计算机系统。6.用小型专用辅助计算机执行例行任务。7.灵活的显示装置和显示服务。本文叙述顺应上述趋势的系统体系结构。模块化设备提供了高速数据通过率,适应复杂格式,与现代32位计算机相容。     

Biosignatures from Earth-like planets around M dwarfs

Coupled one-dimensional photochemical-climate calculations have been performed for hypothetical Earth-like planets around M dwarfs. Visible/near-infrared and thermal-infrared synthetic spectra of these planets were generated to determine which biosignature gases might be observed by a future, space-based telescope. Our star sample included two observed active M dwarfs-AD Leo and GJ 643-and three quiescent model stars. The spectral distribution of these stars in the ultraviolet generates a different photochemistry on these planets. As a result, the biogenic gases CH4, N2O, and CH3Cl have substantially longer lifetimes and higher mixing ratios than on Earth, making them potentially observable by space-based telescopes. On the active M-star planets, an ozone layer similar to Earth's was developed that resulted in a spectroscopic signature comparable to the terrestrial one. The simultaneous detection of O2 (or O3) and a reduced gas in a planet's atmosphere has been suggested as strong evidence for life. Planets circling M stars may be good locations to search for such evidence.     

The feasibility of Doppler monitoring during EVA

During extravehicular activities (EVA) outside the spacecraft, astronauts have to work under reduced pressure in a space suit. This pressure reduction induces the risk of decompression sickness (DCS) by the formation of gas bubbles from excess nitrogen dissolved in the organism by breathing air at normal pressure. Under laboratory conditions the gas bubbles moving in the blood stream can be detected by the non-invasive ultrasonic Doppler method. By early detection of excessive bubble formation the development of DCS symptoms may be prevented by early application of preventative measures. The method could also be useful when applied in the space suit in order to compare the results of laboratory tests with operational results, because there is a discrepancy according to the DCS risk of laboratory experiments and actual EVA missions, where no symptoms have been reported yet. A prototype Doppler sensor has been developed and implemented in the Russian Orlan suit. To investigate the feasibility of this method under simulated space conditions, the equipment has been used in a series of 12 thermovacuum chamber tests with suited subjects, where intravenous bubble formation was compared to unsuited control experiments. In more than 50% of the suited tests good Doppler recordings could be achieved. In some cases with unsatisfying results the signal could be improved by breathholding. Although the results do not yet allow any conclusion about a possible difference between suited and unsuited subjects due to the small number of tests performed, the method proved its feasibility for use in EVA suits and should be further developed to enhance the safety of EVA procedures.     

对大功率航空谐振环路变换器的系统设计考虑

已研制出一种新型变速恒频（VSCF）400Hz飞机发电系统，该系统使用了一种有源箝位谐振直流环变换器。描述了选择谐振变换器功率级最佳配置的设计方法，包括选择满足关键控制性能参数的功率器件值的技术。讨论了变换器各元件之间的相互影响，并且提出了选择的参数值必须满足多方面的、有时甚至是相互矛盾的系统性能指标，并通过60kVA实验系统的仿真和测试数据验证了该系统的可行性。     

液氧/烃三组元推进剂助推发动机的设计思想

讨论了液氧/烃三组元推进剂助推发动机的设计思想,这种液氧/甲烷助推发动机的初步设计还使用了液氢.试验表明,液氧/甲烷/液氢三组元推进剂发动机具有燃烧稳定、燃烧效率高、冷却性能好、能与铜合金燃烧室壁很好兼容等优点,因而可消除或大大减少设计可重复使用的高压烃类助推发动机时可能出现的风险.     

固体火箭推进剂——西欧发展情况

详细介绍西欧各国研制固体火箭推进剂的情况及其进展.对双基推进剂,包括浇注双基推进剂、压伸双基推进剂、复合改性浇注双基推进剂和复合推进剂,以及一些粘合剂的特性和发展分别作了叙述.探讨在固体推进剂中加入硼粉后性能的改进以及所带来的问题.今后固体推进剂发展的重点将是:提高总固体含量,进一步提高燃速,改进药柱的力学性能,降低温度敏感系数,以及降低推进剂成本.     

84英寸推进剂药筒与药柱 第一卷 技术讨论

1.0 绪言先进洲际导弹的设计要求使用比现用导弹系统发动机性能更高的固体火箭发动机。这些高性能的发动机将(1)采用高固体含量的先进推进剂,(2)有较高的火焰温度和(3)在相当高的燃烧室压力下工作。因此,先进发动机的喷管和推力向量控制部件所面临的环境将远比现有系统要恶劣得多。为了正确地评价这些先进设计的性能,必须对这些部件在相当苛刻的工作条件下进行大量的鉴定试验,以便模拟实际应用的情况。为此,空军火箭推进实验室(AFRPL)终于研制了