民用飞机复合材料结构制造工艺变化的等效性验证

高性能复合材料已经大量应用于民用运输飞机结构,并以飞机主制造商协同供应商的方式进行复合材料飞机结构的制造。介绍了航空器适航审定对复合材料结构制造的适航要求,引出了复合材料结构制造工艺变化的等效性验证方法。目前,复合材料结构制造工艺变化的等效性验证是通过所制造复合材料物理的、化学和基本力学的性能试验,并对试验结果进行统计分析来实现的。最后提供了等效性验证的接受准则。所述内容,对国内民用飞机复合材料结构在不同供应商处制造以及制造过程中工艺变化如何满足航空器适航审定要求提供借鉴;对其它行业复合材料结构制造的质量控制也有借鉴意义。     

Stability analysis of an aeroelastic system with friction

In this paper, harmonic balance method, exact formulation and numerical simulation method are adopted to study the effects of different friction stiffness on the stability of 1.5 degrees of freedom aeroelastic system. On this basis, the expressions of input energy and dissipated energy are deduced, and the energy method is used to reveal the mechanisms of the stable boundary and unstable boundary existing in the system and the effects of different friction stiffness on the stability of the system. Studies have shown that the stability region and the critical aerodynamic damping ratio of the system rise with the increase of the friction stiffness, while the friction stiffness has little effect on the stability boundary. In the analysis of the stability of system, the results of harmonic balance method, exact formulation and Newmark of numerical simulation method are in good agreement. Compared with exact formulation and numerical simulation method, the concept and conclusion of harmonic balance method are simple in the system stability analysis.     

空中乘务专业考生面试技能技巧及注意事项

空中乘务专业与其他非艺术类专业的最大区别在于考生必须参加招生院校组织的专业面试,同时也与航空公司招乘面试有所不同.招生面试是有愿望就读正规院校空中乘务专业学生的必经之路,正确把握、充分准备、良好发挥,有利于在面试中得到好的印象和取得好的效果.     

航天飞行器中舷窗温度场及换热的研究：外部界面处于第三类非线性边界条件

本文采用控制容积法,光线踪迹法结合谱带模型,研究航天飞机返回大气层时舷窗硅玻璃的非稳态复合换热。文章给出了界面S_2处于第三类非线性边界条件下,舷窗硅玻璃内部的温度场和进入机舱内部的热流密度。计算结果表明,如不考虑硅玻璃内部的辐射作用,对温度场影响不太大,但对进入机舱内的热流密度将会产生很大的误差。     

用高速纹影摄影技术观测自由面微物质的喷射

本文介绍了适于爆轰实验研究的透射式高速纹影仪。该设备具有较高的测试灵敏度。应用它观测了铅和钢样品自由面的微物质喷射现象,取得了好的结果。     

冲压发动机转级技术研究现状与展望

冲压发动机的转级技术是各类超声速、高超声速飞行器研制所面临的一类技术难题。为了系统性地研究冲压发动机转级技术的研究现状,总结了冲压发动机在转级过程气动方案设计、进气道流动分析、转级时序设计等方面所面临的关键技术问题,综述了国内外研究进展情况,在此基础上指出了当前在超燃冲压发动机转级技术研究、转级过程数值仿真、地面试验等方面存在的不足,对后续研究工作进行了展望。     

高教机天线布局影响通讯距离研究与改进

某型高级教练机在试飞中,出现空地通讯距离不满足战技指标要求的问题。经过分析发现,由于超短波电台天线作为单极天线,其安装布局未满足天线本身要求,即接地面尺寸过小、近场区环境复杂等,导致天线辐射性能受到影响。本文对天线阻抗和方向性系数进行了研究分析,并根据飞机情况制定相应的改进方案。     

The Role of Magnetic Reconnection in CME Acceleration

Observations carried out from the coronagraphs on board space missions (LASCO/SOHO, Solar Maximum and Skylab) and ground-based facilities (HAO/Mauna Loa Observatory) show that coronal mass ejections (CMEs) can be classified into two classes based on their kinematics evolution. These two classes of CMEs are so-called fast and slow CMEs. The fast CME starts with a high initial speed that remains more or less constant; it is also called the constant-speed CME. On the other hand, the slow CME starts with a low initial speed, but shows a gradual acceleration; it is also called the accelerated and slow CME. Low and Zhang [Astrophys. J. 564, L53–L56, 2002] suggested that these two classes of CMEs could be a result of a difference in the initial topology of the magnetic fields associated with the underlying quiescent prominences. A normal prominence magnetic field topology will lead to a fast CME, while an inverse quiescent prominence results in a slow CME, because of the nature of the magnetic reconnection processes. In a recent study given by Wu et al. [Solar Phys. 225, 157–175, 2004], it was shown that an inverse quiescent prominence magnetic topology also could produce a fast CME. In this study, we perform a numerical MHD simulation for CMEs occurring in both normal and inverse quiescent prominence magnetic topology. This study demonstrates three major physical processes responsible for destabilization of these two types of prominence magnetic field topologies that can launch CMEs. These three initiation processes are identical to those used by Wu et al. [Solar Phys. 225, 157–175, 2004]. The simulations show that both fast and slow CMEs can be initiated from these two different types of magnetic topologies. However, the normal quiescent prominence magnetic topology does show the possibility for launching a reconnection island (or secondary O-line) that might be thought of as a “CME’’.     

大口径远程榴弹气动力-外弹道综合优化设计

在大口径远程榴弹设计中,在保证弹丸具有足够的威力,飞行稳定性和发射强度的前提下,使弹丸具有最大射程是一个很有意义的问题。本文给出了大口径远程榴弹气动力一外弹道综合优化设计数学模型,本文还首次涉及了底部排气弹外形优化问题。