Analytical definition and proposed concept for the manned infrastructure of a lunar outpost

A recent study made by ESA has reviewed the scientific investigations to be only, or best, performed on the Moon (Return to the Moon, ESA SP-1150, June 1992), and has identified the need for a manned lunar outpost to provide support to field geologists in sampling and in-situ observations of the lunar surface, and to allow the refurbishments of surface stations and rovers. Planning and development for a manned outpost on the Moon requires an in-depth understanding and analysis of the functions this outpost is expected to perform. We therefore analyzed the impact of the proposed scientific investigations on the design of a manned lunar outpost. The specific questions raised in our study were: What are the medical, physiological and psychological risks for a crew to stay and to work on the Moon? What transit and lunar surface infrastructures (habitats and vehicles) are needed to minimize those risks?     

Adaptational changes in the neural control of cardiorespiratory function in a confined environment: the CNEC#3 experiment

The goal of the study was to characterize the changes in neurovegetative control of the circulation, attending the presumed physiological and psychological stress originated by the isolation and confinement typical of the living condition of space stations, as simulated in a ground based unit, using time and frequency domain analysis. As a secondary goal we sought to verify the implementation of real time data acquisition, for off line spectral analisys of R-R interval, systolic arterial pressure (by Finapres) and respiration (by PVF2 piezoelectric sensors).

We addressed the cardiorespiratory and neurovegetative responses to standardized, simple Stressors (active standing, dynamic and static handgrip) on the EXEMSI 92 crew, before, during and after the isolation period.

On average the appropriate excitatory responses (to stand, dynamic and static handgrip) were elicited also in isolation and confinement.

Active standing and small masses muscular exercises are easy to be performed in a confined and isolated environment and provide a valuable tool for investigating the adaptational changes in neural control mechanisms.

The possibility there exists of using this time and frequency domain approach to monitor the level of performance and well being of the space crew in (quasi) real time.     

欧洲计算流体力学——个人观点

介绍了70年代初到20世纪末欧洲科学家对CFD发展的主要贡献,并重点关注了对国际流体力学数值方法会议(ICNMFD)和国际计算力学学术会议(ISCFD)的成功举办具有重大贡献的科学家.ICNMFD始于1969年(新西伯利亚),由参与了美国和苏联太空竞赛的两国科学家联合创办,而ISCFD则作为ICNMFD在亚太地区的同类会议初创于1995年(东京).由Oshima教授和本人提议,得益于上述两个会议全体科学委员会成员的共同努力,ICNMFD和ISCFD自2000年开始,合并成为每两年举办一次的国际计算流体力学会议(ICCFD).绝大部分本文讨论所涉及的学者通常都在受邀进行大会报告后,成为了前述三大国际会议中的一个或多个科学委员会的成员.作者对文中讨论所涉及的研究人员的圈定负有全权责任,上述人员的选择更多地基于应用而非理论计算流体力学,因此尚存在不完善之处.此外由于文中所讨论的学者大都是作者在40多年计算流体力学研究生涯中的私交好友,因此并没有将年轻一代的科学家考虑进来,但这并非由于他们的贡献不重要.另外值得注意的是欧洲的计算流体力学同美国的计算流体力学有非常紧密的联系,本文讨论所涉及的研究学者有些最早从欧洲开始涉足计算流体力学而现在则生活和工作于美国(例如Glowinski,Roe,Van Leer等人),而有些则是在美国取得了博士学位(例如Launder,Napolitano),他们都同美国的科学家进行过合作,因此很难清晰地对欧洲和美国的计算流体力学进行界定.对那些现已移居美国的欧洲科学家们,本文优先考虑了他们移居之前的贡献.最后但并非是最不重要的,作者通过电子邮件一一联系了文中所涉及的科学家,希望他们本人能够给出其自身贡献的评价草稿,从而帮助作者以最权威的视角在文中相应章节对其工作进行评述.本文向提供自述评价的诸位致以谢意,同时也希望其他同仁能够对本人不恰当的擅自评述给予谅解.     

含摩擦和加热的跨声速流动数值模拟研究

喷管中跨声速流动的反应流体动力学是实验和理论研究的一个重要领域.本文主要由两部分构成,在第一部分中对文献[2]中的Murman格式[1]的一般形式进行了简化,得到了守恒形式的欧拉方程,并对其求解方法进行了讨论,同时针对Chattot等的工作展开了分析,并给出了带激波的流动计算结果;而文章的第二部分则研究了包含摩擦、加热以及耗散的跨声速流动,并重点关注了一步Arrhenius化学反应模型下的爆震现象.本文还探究了摩擦力和带燃烧的跨声速流动之间的相互作用,同时详细给出了新的欧拉方程数值求解算法并同已有文献算例进行了对比验证.     

预测固体推进剂火箭发动机侵蚀燃烧的数值法

对于固体推进剂火箭燃烧可采用一维模型预测固体推进剂火箭发动机的侵蚀燃烧特性。用取决于不同燃烧速率的速度来表示固体推进剂的侵蚀燃烧。数值积分控制偏微分方程就可得到分析结果。使用非定常公式预测固体推进剂侵蚀燃烧特性。计算了各种不同药形的复合推进剂和双基推进剂的侵蚀燃烧特性。测出了各种不同药形装填密度(药柱初始通孔面积与喉面积之比)对压力时间曲线的影响。现有分析指出,装填密度是确定某一特定药形及化学成分的推进剂侵蚀燃烧特性的最重要参数之一。研究表明低燃速推进剂比高燃速推进剂反映出具有较大的侵蚀燃烧效应。同时也表明长方药形与圆柱药形相比具有较大的初始压力峰,相反压力很快就稳定到一般与装填密度无关的平衡压力。     

固体推进剂断裂前的特性

前言在固体推进剂药柱中,一个通常遇到的结构问题是大断裂的发生和增长。要弄清此问题,也研究推进剂断裂前的特性。按研究大纲,分三个阶段进行理论和实验研究。本文涉及第一阶段企图做的和已完成的工作。即建立一个数学模型,将其应用于固体推进剂在应力作用下的单个断裂前的结构形式上,在聚合物系统中具有此种断裂前结构形式的谓之裂纹。同时研究了一种实验技术,用以测定在裂纹附近的位移场和应力场。     

美国固体推进剂的检验与鉴定规程

美国建立了测定固体推进剂的化学、物理和界面等各项性能的标准检验规程。对推进剂来说,所产生的整套数据,必须是充分的,而且足以确保其安全、工艺参数,并满足质量鉴定指标。固体推进剂的安全、化学、物理、力学等各项性能的检验,是与特定的发动机指标相联系的。测试项目的选择取决于推进剂的类型(如单基或双基,复合或复合改性双基),发动机使用条件(如密闭或不密闭的发动机壳体、相对应的溫度及高度的点火条件),以及要求的贮存寿命。目前,美国对推进剂的检验和鉴定大约进行六十种测试。本文提出了检验与鉴定准则的概要,讨论了各项或各类测试的细节与目的。     

Meteors do not break exogenous organic molecules into high yields of diatomics

Meteoroids that dominate the Earth's extraterrestrial mass influx (50-300 microm size range) may have contributed a unique blend of exogenous organic molecules at the time of the origin of life. Such meteoroids are so large that most of their mass is ablated in the Earth's atmosphere. In the process, organic molecules are decomposed and chemically altered to molecules differently from those delivered to the Earth's surface by smaller (<50 microm) micrometeorites and larger (>10 cm) meteorites. The question addressed here is whether the organic matter in these meteoroids is fully decomposed into atoms or diatomic compounds during ablation. If not, then the ablation products made available for prebiotic organic chemistry, and perhaps early biology, might have retained some memory of their astrophysical nature. To test this hypothesis we searched for CN emission in meteor spectra in an airborne experiment during the 2001 Leonid meteor storm. We found that the meteor's light-emitting air plasma, which included products of meteor ablation, contained less than 1 CN molecule for every 30 meteoric iron atoms. This contrasts sharply with the nitrogen/iron ratio of 1:1.2 in the solid matter of comet 1P/Halley. Unless the nitrogen content or the abundance of complex organic matter in the Leonid parent body, comet 55P/Tempel-Tuttle, differs from that in comet 1P/Halley, it appears that very little of that organic nitrogen decomposes into CN molecules during meteor ablation in the rarefied flow conditions that characterize the atmospheric entry of meteoroids approximately 50 microm-10 cm in size. We propose that the organics of such meteoroids survive instead as larger compounds.     

温度敏感性和侵蚀燃烧

减少推进剂初温对固体火箭发动机性能的影响,一段时间以来从推进剂组分来说一直是毫无办法的。最近,无喷管火箭发动机的试验指出,其温度敏感性明显地低于有喷管的发动机。这样我们可以假定,减少发动机温度敏感性的途径可能存在于推进剂组分之外。对无     

固体火箭发动机的实际和预示压力—时间历程之间的差别

固体火箭发动机(SRM_S)中实际的稳态压力——时间历程经常不遵循用经典方程和方法所预示的曲线形状。每个发动机偏离预示压力的最大幅度和时间均不相同。对具有圆柱和星孔形状的分段推进剂药柱的航天飞机固体火箭发动机,本文提出了关于这种偏差的数据。本文对端面燃烧药柱的有关类似情形的数据也进行了讨论。