细长体大迎角绕流的滚转角特性

尖拱和钝拱细长体的截面侧向力分布呈现明显的滚转角效应。不同滚转角下尖拱侧向力沿轴向分布曲线(CC～x/D)的相位和半周期各不相同,截面侧向力随滚转角变化(CC～)呈现一定的无规律性;而钝拱CC～x/D曲线的相位和半周期基本相同,但振幅值大小依赖于滚转角,CC～分布呈完全的无规律性。尖拱模型头部的加工精度导致的微扰动使得尖拱CC～x/D分布变成型式基本一致的两簇曲线,其特征点和半周期分别对应相同,CC～分布呈现典型的双周期方波。     

有限大平板中圆孔的应力集中计算

本文应用广义变分原理,给出了含圆孔的有限大平板应力集中的计算公式。並对矩形板单向均匀拉伸和剪切两种情况进行了数值计算,将计算结果绘成了曲线。     

可修系统的可用度分析方法研究

介绍了一种新的可修系统可用度分析方法--可修系统动态故障树建模分析方法.为了获得高的可靠性和可用性,计算机控制系统大量采用了动态余度管理、储备及复杂的故障恢复技术,使计算机控制系统呈现出很强的动态性和实时性.采用动态故障树与Markov过程综合方法,将计算机控制系统的动态时序用DFTA(Dynamic Fault Tree Analysis)描述,将系统可修过程用Markov过程描述,将系统分解成若干个小的模块,逐步计算各模块的可用度、等效故障概率和维修率,最后综合进行整个系统的可用度分析.     

大型民机进近着陆段异常能量风险判据研究

根据大型民机事故统计，进近着陆阶段事故率最高，而其中大部分事故首先表现出异常能量状态，并演变成失控、重着陆、擦尾、冲出跑道等事故类型，或者呈现复飞失败。在归纳上述五类终端事故类型作为重点关注对象基础上，建立典型大型民机飞行数值仿真平台，使用随机模拟和相关性分析方法研究能量状态参数偏离导致进近着陆风险的影响规律。在此基础上，根据仿真结果给出了由关键能量参数确定的能量状态安全边界，可建立不同风场条件及可能的复飞油门下由空速-下滑角参数构成的异常能量预警判据，对于异常能量导致的进近着陆风险预警具有准确性和非保守性。研究结果可为大型民机进近着陆过程的风险预警以及相关飞行控制功能设计提供方法基础。     

基于逆模拟分析的民用飞机操纵状态再现研究

民航飞行事故原因调查分析时，常常要对飞机的操纵状态进行再现分析。但由于FDR数据缺失、设备损坏等各类原因，对飞行员的操纵情况并不能准确有效地还原。采用逆模拟技术是解决飞行操纵状态再现分析的有效途径。逆模拟技术是通过已知的系统输出确定动态系统控制输入的计算方法。在众多逆模拟算法中，积分逆模拟算法由于具有模型独立、实现简单而得到广泛应用。对某中型民用运输机采用积分逆模拟方法，对一个简单的飞机操纵进行了再现分析。分析了积分逆模过程中的收敛区间和稳定性，并总结了使用积分逆模拟算法的注意要点。     

从一起飞机滑梯救生包系带问题浅谈人为因素分析

本文就一起看似简单的B757飞机逃离滑梯救生包系带问题未能正确纠正的事件,结合加拿大运输部的人为差错12个"陷阱"(Dirty Dozen),从人为因素的角度进行了简要的分析,为我们在日常航空安全管理中如何系统地分析、解决问题提供了一个案例。     

Long term changes of altimeter range and geophysical corrections at altimetry calibration sites

Accurate sea level trend determination is fundamentally related to calibration of both the instrument as well as to investigate if there are linear trends in the set of standard geophysical and range corrections applied to the sea level observations. Long term changes in range corrections can leak into the observed sea level record and be interpreted as part of the sea level trend. Particularly if these exhibit anomalous trend close to the satellite calibration sites.     

贫困女大学生的心理贫困及教育对策研究

经济贫困女大学生是高校的一个特殊的弱势群体。她们疲惫的身心承受着巨大的经济和心理压力。以沈阳航空航天大学511名贫困女大学生为调查对象,对她们的心理问题进行了深入的分析,探讨了通过加强心理健康教育和思想政治教育提高其身心健康水平的策略。     

Building components for an outpost on the Lunar soil by means of a novel 3D printing technology

3D-printing technologies are receiving an always increasing attention in architecture, due to their potential use for direct construction of buildings and other complex structures, also of considerable dimensions, with virtually any shape. Some of these technologies rely on an agglomeration process of inert materials, e.g. sand, through a special binding liquid and this capability is of interest for the space community for its potential application to space exploration. In fact, it opens the possibility for exploiting in-situ resources for the construction of buildings in harsh spatial environments. The paper presents the results of a study aimed at assessing the concept of 3D printing technology for building habitats on the Moon using lunar soil, also called regolith. A particular patented 3D-printing technology – D-shape – has been applied, which is, among the existing rapid prototyping systems, the closest to achieving full scale construction of buildings and the physical and chemical characteristics of lunar regolith and terrestrial regolith simulants have been assessed with respect to the working principles of such technology. A novel lunar regolith simulant has also been developed, which almost exactly reproduces the characteristics of the JSC-1A simulant produced in the US. Moreover, tests in air and in vacuum have been performed to demonstrate the occurrence of the reticulation reaction with the regolith simulant. The vacuum tests also showed that evaporation or freezing of the binding liquid can be prevented through a proper injection method. The general requirements of a Moon outpost have been specified, and a preliminary design of the habitat has been developed. Based on such design, a section of the outpost wall has been selected and manufactured at full scale using the D-shape printer and regolith simulant. Test pieces have also been manufactured and their mechanical properties have been assessed.     

Human exploration of near earth asteroids: Mission analysis for chemical and electric propulsion

This paper presents a mission analysis comparison of human missions to asteroids using two distinct architectures. The objective is to determine if either architecture can reduce launch mass with respect to the other, while not sacrificing other performance metrics such as mission duration. One architecture relies on chemical propulsion, the traditional workhorse of space exploration. The second combines chemical and electric propulsion into a hybrid architecture that attempts to utilize the strengths of each, namely the short flight times of chemical propulsion and the propellant efficiency of electric propulsion. The architectures are thoroughly detailed, and accessibility of the known asteroid population is determined for both. The most accessible asteroids are discussed in detail. Aspects such as mission abort scenarios and vehicle reusability are also discussed. Ultimately, it is determined that launch mass can be greatly reduced with the hybrid architecture, without a notable increase in mission duration. This demonstrates that significant performance improvements can be introduced to the next step of human space exploration with realistic electric propulsion system capabilities. This leads to immediate cost savings for human exploration and simultaneously opens a path of technology development that leads to technologies enabling access to even further destinations in the future.