航天器宽带随机振动响应分析

简要概述了航天器宽带随机振动试验和分析的必要性以及国内外预示技术的发展与现状；然后以某卫星为例，利用有限元方法和统计能量分析（SEA）对整星的宽带随机振动学环境进行了预示，经过与试验结果的对比，验证了上述方法的可行性。     

Wave propagation analysis for a second strain gradient rod theory

In this work, an enriched model describing the longitudinal wave propagation is established based on Mindlin’s Second Strain Gradient (SSG) theory, which can describe the heterogeneity caused by the micro-structure interactions in the frame of continuum mechanics. The governing equation and associated boundary conditions are derived based on Hamilton's principle, then the dispersion relation of non-classical longitudinal wave together with the extra-waves appearing exclusively in SSG theory model are investigated. The investigations are based on the modal density, energy flow, and forced response of the rod. Wave transmission and reflection through planar interfaces based on the proposed model have been calculated. Finally, the results of the enriched model are well interpreted by comparing with the classical theory results, and some useful conclusions are derived on the SSG theory based model in the wave propagation characterization.     

动磁式线性电机理论研究与测试技术

本文以昆明物理研究所的SC100H线性斯特林制冷机为研究对象,对该制冷机采用的动磁式线性振荡电机磁路特性进行了理论与实验研究。建立了电机理论模型,对模型进行了结构简化以便于分析计算,利用等效磁路法和机电能量转换原理,分析电机推力特性与动子相对位置等的关系,利用拉力测试系统对电机在不同输入电流的推力特性进行了测试,测试结果与理论值很好的吻合,从而为电机结构参数和运行参数的设计优化提供了设计参考与依据。     

Sandwich module prototype progress for space solar power

Space solar power (SSP) has been broadly defined as the collection of solar energy in space and its wireless transmission for use on earth. This approach potentially gives the benefit of provision of baseload power while avoiding the losses due to the day/night cycle and tropospheric effects that are associated with terrestrial solar power. Proponents have contended that the implementation of such systems could offer energy security, environmental, and technological advantages to those who would undertake their development. Among recent implementations commonly proposed for SSP, the modular symmetrical concentrator (MSC) and other modular concepts have received considerable attention. Each employs an array of modules for performing conversion of concentrated sunlight into microwaves or laser beams for transmission to earth. While prototypes of such modules have been designed and developed previously by several groups, none have been subjected to the challenging conditions inherent to the space environment and the possible solar concentration levels in which an array of modules might be required to operate. The research described herein details our team's efforts in the development of photovoltaic arrays, power electronics, microwave conversion electronics, and antennas for microwave-based “sandwich” module prototypes. The implementation status and testing results of the prototypes are reviewed.     

利用质子强度变化对太阳质子事件进行短期预报方法初步研究

采用GOSE-10卫星4～9 MeV(P2),9～15 MeV(P3),15～40 MeV(P4),40～80 MeV(P5)能段上的质子通量数据,结合质子能谱,对太阳质子事件发生前各能谱参数的变化特征进行分析,详细介绍利用能谱参数的变化特征及能量E>10 MeV的质子通量数据对太阳质子事件进行预报的新方法,并运用这种方法对2002-2006年期间太阳质子事件进行了预报.预报结果显示,预报提前量最多达到100 h以上,对质子事件的报准率达97.5%,预报方法具备一定的有效性和实用性.      

采用变速控制力矩陀螺的一种姿态/能量一体化控制研究

本文研究采用变速控制力矩陀螺（VSCMG）的航天器姿态／能量一体化控制技术。首先建立了以变速控制力矩陀螺为执行机构的航天器姿态动力学模型，并给出了全局稳定的姿态反馈控制律。以控制力矩陀螺群的构型奇异量度为依据，分别考虑了VSCMG的控制力矩陀螺（CMG）工作模式和反作用飞轮（RW）工作模式。在陀螺群接近奇异时启用转子的反作用飞轮工作模式来补偿控制力矩陀螺采用鲁棒伪逆操纵律时所引起的力矩误差；在陀螺群远离奇异状态时，用控制力矩陀螺来补偿转子储能带来的干扰力矩。在姿态控制的同时利用转子的变速特性，完成按照给定的功率存储／释放能量，并在陀螺群远离奇异状态时对储能过程中转子的转速进行调节，以保持良好地动量包络外形。最后以某航天器的姿态控制为例，给出了数值仿真结果。     

一种基于NOMA的Q学习卫星通信随机接入方法

基于非正交多址接入(NOMA)的Q学习(Q-Learning)随机接入方法(NORA-QL)是实现物联网中海量设备泛在接入的一项有效技术.为了解决NORA-QL方法仍存在的传输能效和过载容量较低的问题,提出了一种适合卫星通信网络的改进方法(I-NORA-QL).针对传输功耗高的问题,I-NORA-QL利用卫星广播的全局...     

运载火箭故障模式及制导自适应技术应用分析

为提高制导控制系统在运载火箭全发射任务周期中的智慧水平，提高运载火箭完成任务的鲁棒能力，从不同角度阐述了运载火箭故障模式，创新提出了基于能量属性的故障分类方法。针对不同级别的能量故障提出了对制导控制系统的功能、性能需求。尤其针对小、中级别能量故障，简述了运载火箭故障飞行制导自适应方法应用，包含案例及任务目标变更原则等，并分析了制导自适应技术后续工程化应用的实施途径。基于能量属性的故障分类方法及制导自适应方法可应用于后续中国运载火箭工程研制。     

Drag and energy accommodation coefficients during sunspot maximum

Conditions appropriate to gas-surface interactions on satellite surfaces in orbit have not been successfully duplicated in the laboratory. However, measurements by pressure gauges and mass spectrometers in orbit have revealed enough of the basic physical chemistry that realistic theoretical models of the gas-surface interaction can now be used to calculate physical drag coefficients. The dependence of these drag coefficients on conditions in space can be inferred by comparing the physical drag coefficient of a satellite with a drag coefficient fitted to its observed orbital decay. This study takes advantage of recent data on spheres and attitude stabilized satellites to compare physical drag coefficients with the histories of the orbital decay of several satellites during the recent sunspot maximum. The orbital decay was obtained by fitting, in a least squares sense, the semi-major axis decay inferred from the historical two-line elements acquired by the US Space Surveillance Network. All the principal orbital perturbations were included, namely geopotential harmonics up to the 16th degree and order, third body attraction of the Moon and the Sun, direct solar radiation pressure (with eclipses), and aerodynamic drag, using the Jacchia-Bowman 2006 (JB2006) model to describe the atmospheric density. After adjusting for density model bias, a comparison of the fitted drag coefficient with the physical drag coefficient has yielded values for the energy accommodation coefficient as well as for the physical drag coefficient as a function of altitude during solar maximum conditions. The results are consistent with the altitude and solar cycle variation of atomic oxygen, which is known to be adsorbed on satellite surfaces, affecting both the energy accommodation and angular distribution of the reemitted molecules.     

Aeroelastic prediction and analysis for a transonic fan rotor with the “hot” blade shape

This paper focuses on aeroelastic prediction and analysis for a transonic fan rotor with only its “hot” (running) blade shape available, which is often the case in practical engineering such as in the design stage. Based on an in-house and well-validated CFD solver and a hybrid structural finite element modeling/modal approach, three main aspects are considered with special emphasis on dealing with the “hot” blade shape. First, static aeroelastic analysis is presented for shape transformation between “cold” (manufacturing) and “hot” blades, and influence of the dynamic variation of “hot” shape on evaluated aerodynamic performance is investigated. Second, implementation of the energy method for flutter prediction is given and both a regularly used fixed “hot” shape and a variable “hot” shape are considered. Through comparison, influence of the dynamic variation of “hot” shape on evaluated aeroelastic stability is also investigated. Third, another common way to predict flutter, time-domain method, is used for the same concerned case, from which the predicted flutter characteristics are compared with those from the energy method. A well-publicized axial-flow transonic fan rotor, Rotor 67, is selected as a typical example, and the corresponding numerical results and discussions are presented in detail.