一种飞机升降舵需用功率的计算方法

为提供舵面需用功率的计算依据,对工程作动器的设计提供理论支撑,提出了一种飞机升降舵需用功率的计算方法,通过不同类型飞机实例进行计算。首先,针对不同种类的工况进行阐释,并详述速率计算所用的评价准则;然后,提出带载荷平均速率计算方法步骤,分析铰链力矩特性;最后,通过计算空载速率,分析舵面需用功率,并进行计算分析。计算结果表明,该方法计算出的需用功率不仅保证稳定裕度,且与舵面载荷具有理论相关性,设计结果安全合理,对工程设计具有实用指导意义。     

民用飞机方向舵抗鸟撞分析研究

民用飞机方向舵结构通常位于垂尾后部,通过连接铰链与垂直安定面后缘相连,并通过作动器驱动其偏转,从而为飞机提供偏航力矩。对民用飞机方向舵鸟撞相关适航条款要求进行了分析,明确了方向舵抗鸟撞需要满足的具体要求。在完成上述工作后,对某型民机方向舵的抗鸟撞性能进行了全面的评估。首先通过工程算法,初步评估了该方向舵不同偏角下的鸟体撞击力,并以此为依据筛选出了鸟撞的严酷工况,避免了大量计算方向舵不同偏角的鸟撞情况,从而大大降低了仿真分析的工作量。通过SPH方法,使用PAM-Crash软件对方向舵结构进行了抗鸟撞分析,得到了方向舵翼面本体结构的损伤情况、连接铰链的受载情况和方向舵作动器的受载情况,并以此为依据,完成了对方向舵抗鸟撞性能的完整评估。     

任务规划系统机动模型与航线设计

航空兵任务规划系统中飞机空对地攻击航线解算的准确性、航线生成质量和航线解算速度是衡量任务规划系统能力的重要指标。飞机空对地攻击航线设计是飞机航线规划中典型的多约束复杂机动,其在设计与使用过程中受到来自时间、空间及飞机本体的多维约束,对飞行动力学建模与航迹优化提出了较高的要求。本文利用面向对象的思想对飞机无侧滑动力学模型进行建模,通过航线机动动作拼接、分段优化的方式实现复杂机动过程的设计与优化,并进行仿真分析。结果表明：该航线优化设计能够实现飞机多约束航迹设计与规划功能,迭代优化算法具有较好的收敛性,可满足航空兵任务规划使用要求。     

纳米光催化技术在客机座舱空气质量控制中的应用

纳米光催化技术是一种新型的空气净化技术,近年来已成为空气净化领域的研究热点之一。本文简要介绍了纳米光催化技术的发展历史、净化机理以及国内外的研究进展;分析了实际应用中存在的问题;并指出了纳米光催化技术在客机座舱空气质量控制中的应用前景。     

Discriminating satellite IR anomalies associated with the MS 7.1 Yushu earthquake in China

In the process of exploring pre-earthquake thermal anomalies using satellite infrared data, Blackett et al. (2011) found that the previously reported anomalies before the 2001 Mw 7.7 Gujarat earthquake, in India, were related to positive biases caused by data gaps due to cloud cover and mosaicing of neighboring orbits of MODIS satellite data. They supposed that such effects could also be responsible for other cases. We noted a strip-shaped TIR anomaly on March 17th, 2010, 28?days before the Ms. 7.1 Yushu earthquake (Qin et al., 2011). Here we again investigate multi-year infrared satellite data in different bands to discriminate whether the anomaly is associated with the earthquake, or is only bias caused by the data gaps. From the water vapor images, we find lots of clouds that have TIR anomalies. However, on the cloudiness background, there is an obvious strip-shaped gap matching the tectonic faults almost perfectly. In particular, the animation loops of hourly water vapor images show that the cloud kept moving from west to east, while they never covered the strip-shaped gap. We consider that the cloud with this special spatial pattern should have implied the abnormal signals associated with the seismogenic process. Based on current physical models, the satellite IR anomalies both on TIR and water vapor bands can qualitatively be explained using synthetic mechanisms.     

Flight safety implications of the extreme solar proton event of 23 February 1956

There is considerable speculation about the effects at aircraft altitudes resulting from extreme solar proton events. The ground level event (GLE) of 23 February 1956 (GLE 5), remains the largest solar proton event of the neutron monitor era in terms of its influence on count rates at monitors near sea level. During this GLE the count rate was increased by as much as 4760% (15-min average) at the Leeds monitor relative to the count rate from galactic cosmic radiation (GCR). Two modern models of the event cumulative solar proton spectrum for this event, a 6-parameter fit in energy and a 4-parameter Band fit in rigidity, are compared with 1-h of GCR at solar minimum. While effective doses calculated with CARI-7A for both models at low geomagnetic cutoff rigidities are indeed high when compared with GCR and can exceed recommended exposure limits, both GLE spectra exhibit a much stronger dependence on cutoff rigidity than GCR, and a larger fraction of the dose from neutrons. At locations with cutoff rigidities above 4.2 and 6.4?GV, respectively, the GLE effective doses are smaller than the GCR hourly dose. At locations with cutoff rigidities above about 4?GV, GCR was the dominant source of exposure in 10?h or less at all altitudes examined. This suggests that if a similar event occurs in the future, low- and mid-latitude flights at modern jet flight altitudes could be well-protected by Earth’s magnetic field.     

A method in near-surface estimation of air temperature (NEAT) in times following the satellite passing time using MODIS images

Air temperature is one of the most important parameters in environmental, agricultural and water resources studies. This information is not usually always available at the required temporal and spatial resolution. The air temperature is measured at a fixed point in the meteorological stations which are dispersed and may not have the appropriate spatial resolution needed for many applications. On the other hand, MODIS satellite images have relatively acceptable spatial resolution specially for use in environmental studies. There is a methodology with which the near surface air temperature can be extracted from MODIS images at the satellite passing time with an acceptable accuracy. The goal in this study is to find a way to predict the air temperature in times after/before the satellite passing time. The procedure consists of two steps. In the first step, the relationship between the air temperature at a time in a synoptic station and the air temperature in other times up to 5 h later were modeled. In the second step, using these built up relationships, the air temperature extracted from the satellite image at the passing time was extrapolated to the next hours. Finally, the results of this extrapolation method were evaluated using the air temperatures measured at those hours and in the pixels containing some other meteorological stations. The error of the method when applied to a relatively homogeneous surface cover was about 1.5 °C. This error when applied to the next hours, was below 2 °C up to 5 h after satellite passing time. This method can be useful in some agricultural and horticultural applications in which both the spatial and temporal resolution are needed simultaneously. This product is a useful tool for frost prediction, a phenomenon that usually happens at night or early in the morning.     

Network analysis of Chinese air transport delay propagation

The Chinese air transport system has witnessed an important evolution in the last dec-ade, with a strong increase in the number of flights operated and a consequent reduction of their punctuality. In this contribution, we propose modelling the process of delay propagation by using complex networks, in which nodes are associated to airports, and links between pairs of them are assigned when a delay propagation is detected. Delay time series are analysed through the well-known Granger Causality, which allows detecting if one time series is causing the dynamics observed in a second one. Results indicate that delays are mostly propagated from small and regio-nal airports, and through flights operated by turbo-prop aircraft. These insights can be used to design strategies for delay propagation dampening, as for instance by including small airports into the system's Collaborative Decision Making.     

攻击机作战效能评估的顶层数学模型

讨论了研究攻击机作战效能时所需要解决的基本问题,给出了描述战区云层分布规律,地形分布规律及侧向参数分布规律的数学模型,研究了机载空对地武器可攻击区,攻击机首攻概率及最大发现目标概率的确定方法,建立了在目标区存在主空系统时计算攻击机攻击效能指标的数学模型。     

用于飞行器横滚稳定控制的组合陀螺舵研究

在传统单转子陀螺舵的基础上,通过仿真分析和虚拟试验,对陀螺转子数量、结构参数、组合形式和空间布局等进行了多学科优化设计,形成了一系列多转子组合陀螺舵,突破了传统单转子陀螺舵控制能力较小、应用范围受限的现状,提高了其对飞行器横滚稳定控制的能力;针对几种典型飞行器的约束条件,通过组合陀螺舵的设计应用,使其横滚衰减因子达到0.002以上,具有良好的横滚稳定性,有助于推动组合陀螺舵在航天飞行器领域的应用和创新。