自由飞试验模型惯性矩的测定

作者根据多年来自由飞试验的实践,叙述了自由飞模型惯性矩的调试、计算、误差分析与处理的经验与方法。     

新一代民用客机自主式数据总线

本文在简要阐述 ARINC 429 和 MIL-STD-1553B 总线应用所受限制的基础上,介绍了90年代美国民航界推出的一种自主式数据总线 ARINc629的设计要点,包括其通信协议。各终端信源数据在总线上的周期传输和非周期传输、信息传输的种类和方法及终端的功能框图,最后给出了此总线在新一代民用机中的应用情况。     

等质量异形粒子超高速撞击侵蚀

用数值方法模拟双锥，圆柱，椭球、圆锥和倒圆锥五类等质量异形铝粒子五种高宽比共２５种粒子对半无限铝靶的超高速撞击侵蚀，撞击速度为４ｋｍ／ｓ，给出了坑深、坑径、坑形参数和坑体积随粒子形状及高宽比的变化曲线。结果与非圆球异形粒子超高速撞击侵蚀计算有重要参考价值。     

J—7LP飞机1：6遥控模型失速尾旋试验

对无动力J—7LP动力学缩比模型进行了遥控试飞,以研究其失速尾旋特性,全偏平尾和方向舵可使模型进八尾旋,舵面全回中即可从各种尾旋中改出。偏转副翼对尾旋特性有明显的影响。     

The Origin of Mercury

Mercury’s unusually high mean density has always been attributed to special circumstances that occurred during the formation of the planet or shortly thereafter, and due to the planet’s close proximity to the Sun. The nature of these special circumstances is still being debated and several scenarios, all proposed more than 20 years ago, have been suggested. In all scenarios, the high mean density is the result of severe fractionation occurring between silicates and iron. It is the origin of this fractionation that is at the centre of the debate: is it due to differences in condensation temperature and/or in material characteristics (e.g. density, strength)? Is it because of mantle evaporation due to the close proximity to the Sun? Or is it due to the blasting off of the mantle during a giant impact? In this paper we investigate, in some detail, the fractionation induced by a giant impact on a proto-Mercury having roughly chondritic elemental abundances. We have extended the previous work on this hypothesis in two significant directions. First, we have considerably increased the resolution of the simulation of the collision itself. Second, we have addressed the fate of the ejecta following the impact by computing the expected reaccretion timescale and comparing it to the removal timescale from gravitational interactions with other planets (essentially Venus) and the Poynting–Robertson effect. To compute the latter, we have determined the expected size distribution of the condensates formed during the cooling of the expanding vapor cloud generated by the impact. We find that, even though some ejected material will be reaccreted, the removal of the mantle of proto-Mercury following a giant impact can indeed lead to the required long-term fractionation between silicates and iron and therefore account for the anomalously high mean density of the planet. Detailed coupled dynamical–chemical modeling of this formation mechanism should be carried out in such a way as to allow explicit testing of the giant impact hypothesis by forthcoming space missions (e.g. MESSENGER and BepiColombo).     

飞机主操纵系统疲劳试验载荷谱小操纵位移频次问题研究

针对飞机全机主操纵系统疲劳试验载荷谱中小操纵位移频次影响问题进行了分析和讨论,确定了某机全机主操纵系统小操纵位移频次的级别。同时,在原某机全机主操纵系统疲劳试验载荷谱的基础上再次对其小操纵位移频次进行了计算,去掉了这一级别以下对全机主操纵系统疲劳试验无影响的小操纵位移频次,从而完善了主操纵系统疲劳试验载荷谱。另外,对小操纵位移频次问题研究结果在其全机主操纵系统疲劳试验中的实施效果进行了阐述。     

工业远程监控系统实施新方案

近期远程监控系统在工业中逐步推广,针对工业系统的特点和工业网络的实际情况,在原有工业系统的基础上,增加现场设备区域的图像监控和数据传输功能,提出了一种工业远程监控系统实施方案。本文论述了该系统的结构、原理及实现方法,经具体实施证明,本文提出的方案已基本能够满足一个通用的基于公用网络的远程视频监控系统的要求,体现了较重要的理论价值和很强的工程实用价值。     

Modelling of Ejecta as a Space Debris Source

When a micro-debris or a micrometeoroid impacts a spacecraft surface, a large number of secondary particles, called ejecta, are produced. These particles can contribute to a modification of the debris environment: either locally by the occurrence of secondary impacts on the components of complex and large space structures, or at great distance by the formation of a population of small orbital debris. This paper describes firstly, the ejecta overall production, and secondly, the lifetime and the orbital evolution of the particles. Finally the repartition of ejecta in LEO is computed. Some results describing the population as a function of size and altitude are presented.     

空战机动动作库设计方式研究

具体阐述了两类常见空战动作库的设计 :典型战术动作库和基本操作动作库 ,详细分析了这两类空战机动动作库的不足 ,最后提出了改进动作库设计的具体意见和建议。     

低空突防任务下综合飞行/推进系统的建模与仿真

建立了综合飞行／推进系统的数学模型，介绍了飞机全维非线性数学模型和涡轮风扇发动机非线性部件级数学模型的建模及综合方法。对飞机执行地形中随任务时，飞行员调节飞行速度的方法与基于总能量的调节飞行速度的方法进行了比较。结果表明，基于总能量的方法比飞行员直接控制飞行速度能够减小发动机的燃油消耗，降低发动机的磨损，进而可以增加飞机的航程，延长发动机的使用寿命。