导弹质量矩控制技术发展综述

质量矩技术是近年来导弹控制领域研究的热点问题之一。它是通过调整弹体内部活动质 量块的状态来实现导弹机动飞行的。与传统的气动舵控制方式相比,它具有响应快、气动外 形简单、无舵面烧蚀问题等优点,在大气层内高超声速飞行控制领域具有广阔的应用前景。 简述了质量矩技术的原理及应用领域,回顾了导弹质量矩控制技术的发展历程;从总体 布局、动力学建模、控制系统设计等方面综合分析了质量矩技术的研究现状;提出了一些当 前需要解决的难点问题,供相关人员参考。
     

直射式气动雾化喷嘴对燃烧室性能的影响

为了深入分析燃油喷嘴对燃气轮机燃烧室性能的影响,针对燃气轮机燃烧室中的直射式气动雾化喷嘴开展了数值模拟,获得了气流流量、燃油流量和气液比对雾化性能的影响规律,喷嘴的雾化性能参数包括雾化粒径和雾化锥角。结果表明：气液比和气流流量对该型喷嘴的雾化性能有显著影响,燃油流量对雾化性能的影响较小;气液两相间相对速度是影响该型喷嘴雾化性能的决定因素,相对速度增大有利于减小雾化粒径,并增大雾化锥角;气流流量和气液比的增大均有利于雾化粒径的减小,燃油流量的增加将使雾化粒径增大;增大气流流量、气液比和减小燃油流量均可使雾化锥角增大;该型喷嘴的雾化锥角变化范围为30.12°～41.24°,雾化粒径变化范围为131.46～ 186.52 μm。喷嘴可实现在较小的雾化锥角变化范围内获得较宽的雾化粒径变化,以此匹配燃气轮机燃烧室不同工作状态,具有较高的实用价值。     

SMESE (SMall Explorer for Solar Eruptions): A microsatellite mission with combined solar payload

The SMESE (SMall Explorer for Solar Eruptions) mission is a microsatellite proposed by France and China. The payload of SMESE consists of three packages: LYOT (a Lyman α imager and a Lyman α coronagraph), DESIR (an Infra-red Telescope working at 35–80 and 100–250 μm), and HEBS (a High Energy Burst Spectrometer working in X- and gamma-rays).     

Evolution of solar wind structures from 0.72 to 1 AU

Understanding the evolution of solar wind structures in the inner heliosphere as they approach the Earth is important to space weather prediction. From the in situ solar wind plasma and magnetic field measurements of Pioneer Venus Orbiter (PVO) at 0.72 AU (1979–1988), and of Wind/Advanced Composition Explorer (ACE) missions at 1 AU (1995–2004), we identify and characterize two major solar wind structures, stream interaction regions (SIRs) and interplanetary coronal mass ejections (ICMEs). The average percentage of SIRs occurring with shocks increases significantly from 3% to 24% as they evolve from 0.72 to 1 AU. The average occurrence rate, radial extent, and bulk velocity variation of SIRs do not change from 0.72 to 1 AU, while peak pressure and magnetic field strength both decrease with the radial evolution of SIRs. Within the 0.28 AU distance from the orbit of Venus to that of Earth, the average fraction of ICMEs with shocks increases from 49% to 66%, and the typical radial extent of ICMEs expands by about a fraction of 1.4, with peak pressure and magnetic field strength decreasing significantly. The mean occurrence rate and expansion velocity of ICMEs do not change from 0.72 to 1 AU.     

Hydrodynamic atmosphere models for hot luminous stars II. Method and improvements over unified models

In a paper submitted to A&A we present the first line blanketed hydrodynamic models of spherically expanding atmospheres of hot stars. This paper is complementary to the submitted paper. Here, we emphasize the advantages and the weak points of our approach and we present additional technical aspects.The models are characterised by a simultaneous solution of the equation of motion, the non-LTE populations of H and He, and radiation transfer in a line blanketed atmosphere. The entire domain from the optically thick photosphere out to the terminal velocity of the wind is treated. The radiative forces are evaluated consistently with the depth-dependent radiation field, taking into account multiple scattering by metal lines and line overlap.     

翼伞归航准则及测风原理探讨

翼伞作为一种新型气动力减速器日渐受到空间回收技术重视。文中给出了具有非比例自动归航控制的翼伞系统的归航准则(考虑到风的影响)以及利用GPS测量数据计算风场的公式。     

Solar and interplanetary precursors of geomagnetic storms in solar cycle 23

Estimating the magnetic storm effectiveness of solar and associated interplanetary phenomena is of practical importance for space weather modelling and prediction. This article presents results of a qualitative and quantitative analysis of the probable causes of geomagnetic storms during the 11-year period of solar cycle 23: 1996–2006. Potential solar causes of 229 magnetic storms (Dst ? −50 nT) were investigated with a particular focus on halo coronal mass ejections (CMEs). A 5-day time window prior to the storm onset was considered to track backward the Sun’s eruptions of halo CMEs using the SOHO/LASCO CMEs catalogue list. Solar and interplanetary (IP) properties associated with halo CMEs were investigated and correlated to the resulting geomagnetic storms (GMS). In addition, a comparative analysis between full and partial halo CME-driven storms is established. The results obtained show that about 83% of intense storms (Dst ? −100 nT) were associated with halo CMEs. For moderate storms (−100 nT < Dst ? −50 nT), only 54% had halo CME background, while the remaining 46% were assumed to be associated with corotating interaction regions (CIRs) or undetected frontside CMEs. It was observed in this study that intense storms were mostly associated with full halo CMEs, while partial halo CMEs were generally followed by moderate storms. This analysis indicates that up to 86% of intense storms were associated with interplanetary coronal mass ejections (ICMEs) at 1 AU, as compared to moderate storms with only 44% of ICME association. Many other quantitative results are presented in this paper, providing an estimate of solar and IP precursor properties of GMS within an average 11-year solar activity cycle. The results of this study constitute a key step towards improving space weather modelling and prediction.     

火星进入舱开伞弹伞载荷动力放大系数研究与试验验证

首先推导了单自由度系统在矩形和半正弦波形脉冲冲击下响应谱动力放大系数与脉冲作用时间的理论解析公式,然后采用有限元显示冲击动力学分析方法,分析了火星探测器进入舱进入过程中开伞弹伞低频大冲击载荷的载荷波形、脉冲作用时间以及结构阻尼对进入舱主结构动力放大系数的影响;最后介绍了开伞载荷悬吊冲坠模拟冲击动载试验和弹伞载荷真实弹伞...     

联盟号载人飞船降落伞系统介绍和分析

文章主要根据俄罗斯航空出口商品广告说明书和专家讲课内容记录汇编而成。文中介绍了联盟号载人飞船降落伞系统的主要技术指标、组成、功能、工作程序;并对其技术特点进行分析研究,提出了个人的见解。     

物—伞系统运动方程与稳定性判据

物—伞系统运动轨迹计算与运动稳定性分析是飞行器回收系统设计的重要课题。文章采用刚体─刚体模型代替物─个系统，给出该系统的运动方程与稳定性判据。