三维抛物化N-S方程全隐格式矢通量分裂求解

采用全隐格式的矢通量分裂算法,在通用曲线坐标系内求解三维无因次抛物化强守恒型N-S(Navier-Stokes)方程.所建立的计算程序,可计算较为复杂边界的三维流场,如求解亚、跨、超音速共存的流场,分区模拟内外流共存流动及其混合剪切尾流.给出了一轴对称亚跨超音速喷管内流场的计算结果,包括计算网格,流矢分布,压力、温度和马赫数等值线分布.也给出了一喷管内外流及其混合尾流的计算结果,包括计算网格,流矢分布,无因次压力、密度和温度等值线分布.     

地磁长期变化引起的低高度卫星轨道辐射带粒子环境的变化

利用IGRF2000模式计算了几个典型轨道辐射带粒子环境并与IGRF1970模式计算的结果进行了比较。计算结果表明，在辐射带的低部，对应某些倾角的能量大于0．1MeV质子的轨道积分通量变化达到2个量级，而通量大10MeV的辐射带质子的轨道积分通量变化达到1个量级；轨道积分通量的最大值变化为1个量级。能量大于0．04MeV辐射带电子的轨道积分通量变化在某些倾角达到3个量级，但轨道积分最大值的变化低于1个量级。1000km以上高度辐射带粒子环境的变化很小。     

PIB模型在空间碎片环境建模中的运用

运用“箱中粒子”模型（PIB）对空间碎片环境的演变趋势进行了研究。首先介绍了PIB半解析性的模型：在建模过程中，把空间碎片的运动视为在一巨大箱体中任意运动的粒子，有其自身输入输出机制；随后，对近地轨道碎片环境进行多层多种类碎片的划分，在此基础上将PIB模型运用于近地轨道环境中，建立多层，分类PIB模型；利用国外文献中的观测资料进行仿真，对未来空间碎片环境的演变作出了预测。     

日本JEM舱空间碎片防护结构设计综述

综述目前国际空间站上日本试验舱有关微流星体及空间碎片的防护技术以及发展趋势,着重探讨防护结构的研究成果,为在轨防护技术提供技术参考。     

低地轨道空间碎片环境建模与分析

根据“箱中粒子”（PIB）的模型和气体分子运动学理论，建立了估算低地轨道（LEO）上空间碎片总数的微分方程，参考国外文献提供的有关空间碎片统计数据和初始条件，求解方程，并分析了空间碎片环境的短期和长期变化趋势。     

Protecting spacecraft against meteoroid/orbital debris impact damage: an overview

Meteoroids and orbital debris pose a serious damage threat to all spacecraft. The effects of a meteoroid/orbital debris (M/OD) impact depend on a variety of factors, including where the M/OD impact occurs, the size, composition, and speed of the impacting object, and the function of the impacted spacecraft system. These effects can be minimal, can degrade a functional spacecraft component, or can compromise spacecraft functionality, even to the point of mission loss or loss of life. To minimize the damage threat from the meteoroid/orbital debris environment, it is often necessary to install protective shielding around critical spacecraft systems. If a system cannot be shielded, operational constraints may need to be imposed to reduce the damage threat. This paper presents an overview of the research and development activities performed since the late 1950s with an aim of increasing the level of protection afforded satellites and spacecraft operating in the M/OD environment and ultimately mitigating the mechanical and structural effects of an M/OD impact.     

球形弹丸高速撞击航天器防护结构的数值模拟分析

给出了空间碎片超高速撞击航天器双层防护结构模型，采用非线性有限元方法中的光滑粒子流体动力算法，计算了球形弹丸对航天器双层防护墙结构超高速撞击过程，获得了弹丸穿过第一层防护墙后，碎裂形成颗粒云团及其对第二层防护墙的损伤效应。计算结果表明多层防护墙结构能够有效地缓减高速空间碎片对航天器的破坏作用。     

对美国宇航公司使用的轨道碎片模型的评价

文章介绍了碰撞程序和碎片程序,并进行了评价。前一个程序说明了碎片撞击的破裂特性;后一个程序给出了当一个空间物体进入碎片云时的撞击概率。     

Assessing the Impact Risk of Orbital Debris on Space Tethers

Tethers are being proposed for a growing number of space applications. However, they may be particularly vulnerable to orbital debris and meteoroid impacts. In order to provide useful reference data for tether systems design, detailed analytical and numerical computations were carried out to assess the average impact rate of artificial debris and meteoroids. The specific geometric properties of tethers as debris targets, when compared to typical satellites, are discussed, and the results obtained are presented in tabular form, as a function of debris size and tether diameter.The computations were carried out for six circular orbits, spanning three altitudes (600, 800 and 1000km) and two inclinations (30° and 50°). Tether diameters in between 1mm and 2cm and debris larger than 0.1mm were considered in the analysis. The collision risk of tethers with spacecraft and upper stages in orbit was estimated as well.In the debris interval and orbital regimes considered, artificial debris represent the dominant contributor to the impact rate. At 600km and in the 0.1–10mm size range, the meteoroid and orbital debris impact rates are still comparable; however, at higher altitudes and in the 1–10cm size range, meteoroids contribute 20–30 times less to the collision probability.The results obtained confirm that for single-strand tethers in low Earth orbit the probability to be severed by orbital debris and meteoroid impacts is quite significant, making necessary the adoption of innovative designs for long duration missions.