Long-term variations of asymmetry of the solar magnetic field and geometry of the interplanetary magnetic field

A comparative analysis of variations of the mean solar magnetic field and the interplanetary magnetic field over all history of their measurements is performed. Asymmetry of the solar magnetic field and its manifestation in the heliosphere is investigated. Long-term variations of the solar magnetic field and the heliosphere, which manifest themselves in alternation of dominating magnetic polarities of different sign, are discovered. On the basis of the analysis of cumulative sums of the IMF components, long-term variations of the IMF geometry and of the solar wind spiral angle are found. The cumulative sum of the IMF B _z component perpendicular to the ecliptic plane also shows long-term variations. Time intervals are revealed, in which negative values of the IMF B _z component dominate, and an increased geomagnetic activity is observed.     

Instability of entropy waves in cosmic plasma

A dispersion equation is derived for small disturbances of the magnetohydrodynamic type in optically transparent plasma with cosmic abundance of elements. The electron heat conductivity along the magnetic field and proton heat conductivity across the field are taken into account. It is shown that entropy waves increase exponentially in wide ranges of temperatures and densities of the cosmic plasma. Manifestations of instability of the entropy waves in the cosmic plasma are discussed.     

Determination of two Satellites’ relative motion using tracking measurements

A technique to determine the initial relative velocity of two satellites at the initial time instant, based on the results of NORAD system’s measurements, is presented. The determination of a relative initial position is shown to result in the unsatisfactory accuracy. This technique is applied to determining the initial velocity of separation of the first Russian nanosatellite TNS-0 from the International Space Station.     

Multi-structural estimation of an integrated navigation system of a reusable spacecraft

An approach to the synthesis of an integrated navigation system is considered for a reusable space-craft that performs an arbitrary spatial maneuver under the conditions of internal and external disturbances. The offered approach provides for a noise-suppressing solution of the navigation problem, both in a regular mode of spacecraft motion, and during its descent along the unplanned trajectory.     

低雷诺数分布式螺旋桨滑流气动影响

以高空长航时（HALE）太阳能无人机（UAVs）研究为背景,采用基于混合网格技术及k-k_L-ω转捩模型求解雷诺平均Navier-Stokes（RANS）方程的多重参考系（MRF）方法,对3种螺旋桨-机翼构型的低雷诺数气动特性进行了高精度准定常数值模拟,在等拉力前提条件下,通过对比机翼气动力系数及表面流场结构特征分析了分布式螺旋桨（DEP）滑流对FX63-137机翼的气动影响。研究表明：螺旋桨滑流影响使得桨后总压及流速显著增大,这是机翼升力增大的主要原因,但同时机翼阻力特性急剧恶化,升阻比反而降低;螺旋桨滑流向机翼边界层内注入丰富湍动能从而抑制流动分离,扩大机翼表面湍流范围及附着流动区域;分布式螺旋桨滑流与低雷诺数机翼表面复杂流动相互作用显著,主要表现为滑流区域边界展向涡结构的产生。     

16Co14Ni10Cr2Mo钢在510℃长期回火变脆的研究

利用透射电镜、扫描电镜及Ａｕｇｅｒ能谱研究了１６Ｃｏ１４Ｎｉ１０Ｃｒ２Ｍｏ钢在５１０℃回火时间对组织与性能的影响。结果表明：该钢在５１０℃保温超过８ｈ以后，韧性开始降低，直至４００ｈ。５０ｈ以后，在冲击断口上出现沿晶断裂特征，随着时间的延长，这种断裂特征更为严重，其原因主要和Ｐ、Ｓ在晶界偏聚有关。     

一种航空装备使用最优梯次间隔时间计算方法

针对航空装备使用因梯次计划不合理,出现大修积压,影响装备在位率等问题,综合考虑装备在位率要求、大修厂修理能力、装备实际余寿等各项因素,提出了一种装备使用最优梯次间隔计算方法,并通过算例进行了仿真说明。结果表明,该方法可针对实际装备剩余寿命,给出最优梯次间隔时间参考建议,可为装备有效使用提供参考。     

变形翼面内变形的研究现状及关键技术

变形机翼作为未来飞机设计的重要发展方向之一，其机翼面内变形的研究已得到广泛的关注。本文分别从变展长、变掠角、变弦长、组合变形四个方面进行分析，阐述面内变形机翼的国内外研究现状，归纳总结变形机理及优缺点，分析其发展趋势。针对该领域的研究现状以及变形机翼的应用要求，提出变形机翼亟待解决的关键技术，包括变形蒙皮技术、变形机构、智能驱动器、传感器及控制网络，阐述各关键技术的应用要求，分析其现存问题，并对未来发展方向进行归纳；以期为面内变形机翼的设计和应用实现提供部分参考。