加速度对含铝复合推进剂瞬时燃速的影响

本文研究了加速度向量对含铝复合推进剂瞬时燃速的影响.其中包括加速度大小和方向对推进剂瞬时燃速增加率的影响和在同一加速度条件下铝粉粒径、铝粉含量和铝粉形状对瞬时燃速增加率的影响.此外,还对研究结果进行了分析和讨论.     

丁羟复合固体推进剂燃速预估

本文在文献[6]的基础上,进一步讨论了丁羟胶、过氯酸铵、铝粉体系的复合固体推进剂的燃速预估问题.在一定实验和假设条件下提出了可适用于计算这类复合固体推进剂燃速和压力指数的半经验方法.当推进剂中的过氯酸铵、铝粉的含量及颗粒度在一定限度内任意变化时,预示的燃速及压力指数与实测结果基本符合.有关计算过程已编有微机计算程序,可供推进剂设计人员参考使用.     

高速旋转固体发动机低燃速推进剂燃速性能的研究

本文研究了推进剂的降速剂种类及其含量、氧化剂粒度和粒度分布,以及发动机的旋转对低燃速固体推进剂燃速性能的影响.并研究了采用新型药条包覆剂提高推进剂燃速测试精度的方法.在此基础上,研制出稳定的低燃速复合固体推进剂.它具有高的燃速精度,较低的压强指数.文章还指出了发动机的高速旋转(2400r/min)对推进剂的燃速性能和比冲的影响.     

超细铝粉燃烧特性初探

实验和理论分析说明超细铝粉的燃烧特性不同于一般铝粉（Ｄ＝１０－３０μＭ）。其原因是在推进剂燃面铝粉的表面氧化反应产生的热量足以使超细铝粉点火燃烧，所以超细铝粉在剂燃面并发发生明显凝聚行为，而是倾向于单颗铝粒点火。因此，合理使用超细铝粉可使某些推进剂性能得到较明显的改善。     

硝胺复合推进剂燃烧性能

在硝胺/高氯酸铵复合推进剂系统中,关于硝胺对比冲和燃速性能的影响,进行了实验研究。试验所用的推进剂组分包括环三甲撑三硝胺(RDX),环四甲撑四硝胺(HMX),高氯酸铵(AP),铝粉(Al和粘合剂。硝胺/AP推进剂的比冲主要取决于所有组分的配合。RDX虽可略增比冲,然而却降低燃烧产物的温度。硝胺/AP推进剂的燃速主要由AP含量和颗粒度大小所控制,也取决于所用粘合剂的类型。燃速随着AP含量的增加和颗粒度的减小而增大。RDX和HMX的化学元素虽然相同,然而含RDX推进剂的燃速大于含HMX推进剂的燃速。这种差异也可在相同AP含量和相同颗粒度的RDX/AP和HMX/AP推进剂中找到。     

用激光燃速仪测量固体推进剂药条的瞬态燃速

本文扼要介绍了激光燃速仪的特性计算及误差分析,它可在压力变化、压力振荡时,测得固体推进剂药条的瞬态燃速.     

超高燃速固体推进剂研究概况

文中对多孔超高燃速推进剂(μ≥1000mm/s)的研究进展、多孔固体推进剂的研究内容、燃烧特性及有关配方作了介绍。最后总结了多孔超高燃速推进剂在密闭爆发器中和作为火炮随行装药的实验研究结果。     

固体火箭发动机旋转对燃速的影响

从实验和理论两方面探讨了固体火箭发动机旋转对燃速的影响。对含铝复合推进剂在试片发动机、全尺寸装药发动机工作状态下旋转对燃速的影响进行了研究, 获得了大量实验数据。得到以下几点结论:铝粉含量相同时, 燃速敏感性随铝粉粒度增大而增大;铝粉粒度相同时, 燃速敏感性随铝粉含量增大而增大;高燃速推进剂加速度阀值高, 燃速敏感性小。      

组分对硝酸酯增塑聚醚推进剂燃烧性能的影响

通过对氧化剂AP含量及粒径、燃速催化剂种类及含量、铝粉粒度、交联剂及工艺助剂等的调整，对硝酸酯增塑聚醚推进剂的燃烧速度和燃速压强指数进行了研究，结果表明，燃速在7．7～16．7mm／s（7．0MPa）范围内可调，静态燃速压强指数稳定在0．5，最低可达0．41。     

用ACP提高硝胺改性双基推进剂的燃速

通过添加快燃物ACP来提高硝胺改性双基推进剂的燃速，得到了ACP影响推进剂燃速的一般规律：推进剂的燃速随ACP的含量和粒度的增大而增大。运用热分析、扫描电镜、燃烧火焰单幅照相、燃烧波温度分布等分析和测试手段来研究含ACP的硝胺改性双基推进剂的燃烧过程，揭示了ACP提高推进剂燃速的机理：ACP的快速燃烧，使得推进剂燃面增大和传热量增加，导致推进剂燃速增加。     

有翼高超声速再入飞行器气动设计难点问题

有翼高超声速再入飞行器是近年来的研究热点,气动设计是飞行器设计的关键。为了更清楚地认识有翼高超声速再入飞行器气动设计的难点问题,对有翼高超声速再入飞行器的发展、优势及总体任务剖面进行了介绍,从5个方面详细介绍了该类飞行器气动设计的难点问题,包括多约束复杂面对称气动布局设计、高温真实气体效应对气动特性影响、天地差异与天地换算方法、反作用控制系统(RCS)喷流干扰对气动特性的影响以及气动数据不确定度等,简要阐明了这些难点问题对总体设计的重要性以及初步的解决思路,为有翼高超声速再入飞行器气动设计提供了一些参考。     

Simulation and Analysis of Crashworthiness of Fuel Tank for Helicopters

Crashworthiness requirement of fuel tanks is one of the important requirements in helicopter designs. The relations among the protection frame, textile layer and rubber layer of the fuel tank are introduced. Two appropriate FE models are established, one is for an uncovered helicopter fuel tank without protection frame, and the other is for fuel tank with protection frame. The dynamic responses of the two types of fuel tanks impinging on the ground with velocities of 17.3 m/s are numerically simulated for the purpose of analyzing energy-absorbing capabilities of the textile layer and protection frame. The feasibility of the current crashworthiness design of the fuel tank is examined though comparing the dynamic response behaviors of the two fuel tanks.     

The effect of inlet conditions on the flow and heat transfer in multiple rotating cavity with axial throughflow

This paper discusses experimental results from two different build configurations of a heated multiple rotating cavity test rig.Measurements of heat transfer from the discs and tangential velocities are presented.The test rig is a 70% full scale version of a high pressure compressor stack of an axial gas turbine engine.Of particular interest are the internal cylindrical cavities formed by adjacent discs and the interaction of these with a central axial throughflow of cooling air.Tests were carried out for a range of non-dimensional parameters representative of high pressure compressor internal air system flows(Re up to 5×106 and Rez up to 2×105).Two different builds have been tested.The most significant difference between these two build configurations is the size of the annular gap between the(non-rotating) drive shaft and the bores of the discs.The heat transfer data were obtained from thermocouple measurements of surface temperature and a conduction solution method.The velocity measurements were made using a two component,LDA system.The heat transfer results from the discs show differences between the two builds.This is attributed to the wider annular gap allowing more of the throughflow to penetrate into the cavity.There are also significant differences between the radial distributions of tangential velocity in the two builds of the test rig.For the narrow annular gap,there is an increase of non-dimensional tangential velocity V/Ωr with radial location to solid body rotation V/Ωr=1.For the wider annular gap,the non-dimensional velocities show a decrease with radial location to solid body rotation.      

突破技术趋同，波音再现竞争优势

 波音公司面临着来自空客公司的巨大挑战,企业战略性创新才是公司成功的关键。为此波音公司的全部战略性研究集中在扩大产品的差异性上,体现在3个方面：电子化（e-Enabled）运营环境、整体复合材料机身部件的制造技术和支持波音787客机的全球协同环境（GCE）。     

临近空间飞行器测控与信息传输系统频段选择

 临近空间飞行器是高性能信息化武器平台,测控（TT&;C）与信息传输系统是其信息保障的核心,而选择合理、可行的频段是展开系统设计的前提和基础。频段选择影响到整个技术方案的制定,是一个需综合考虑、影响深远并具有战略意义的关键问题,从国际电联（ITU）国际标准、高速数传、接收信噪比（SNR）、“三抗”、超视距中继、黑障、雨衰以及设备研制成熟度8个方面全面、细致论证了近空间平台测控系统的频段选择问题,最终得出在视距链路中以Ka频段为宜,在超视距链路中以Ku/Ka双频段为宜的结论。     

基于弯曲激波压缩系统的高超声速进气道反设计研究进展

总结了近十年来弯曲激波压缩研究的主要成果。提出了弯曲激波压缩系统的新概念,即利用特殊设计的楔形弯曲压缩面或空间弯曲压缩面,产生一系列与前缘弱激波相互交汇或叠加的压缩波系,从而使前缘激波弯曲,形成特殊的弯曲激波,它与波后的等熵压缩波来共同完成对气流的压缩。在此基础上,实现了由给定出口气动参数的超声速内流道反设计,实现了由给定压缩面压力分布和给定压缩面马赫数分布要求的型面反设计,实现了由给定激波波面的压缩型面反设计。研究证明,弯曲压缩面-弯曲激波压缩系统具有良好的综合气动性能,为高性能高超声速进气系统的气动设计提供了一种全新的设计方法。     

Experimental Study on Effects of Fuel Injection on Scramjet Combustor Performance

In order to investigate the effects of fuel injection distribution on the scramjet combustor performance, there are conducted three sets of test on a hydrocarbon fueled direct-connect scramjet test facility. The results of Test A, whose fuel injection is carried out with injectors located on the top-wall and the bottom-wall, show that the fuel injection with an appropriate close-front and centralized distribution would be of much help to optimize combustor performances. The results of Test B, whose fuel injection is performed at the optimal injection locations found in Test A, with a given equivalence ratio and different injection proportions for each injector, show that this injection mode is of little benefit to improve combustor performances. The results of Test C with a circumferential fuel injection distribution displaies the possibility of ameliorating combustor performance. By analyzing the effects of injection location parameters on combustor performances on the base of the data of Test C, it is clear that the injector location has strong coupled influences on combus- tor performances. In addition, an inner-force synthesis specific impulse is used to reduce the errors caused by the disturbance of fuel supply and working state of air heater while assessing combustor performances.     

(高)超声速流动试验技术及研究进展

近年来,与高速飞行器相关的(高)超声速流动受到了极大的关注。这类流动所具有的非定常性、强梯度和可压缩性对试验方法和风洞设计技术提出了挑战。超声速纳米示踪平面激光散射(NPLS)技术是由作者所在团队研发的非接触光学测试技术。它能够以较高的空间分辨率来揭示超声速三维流场的一个瞬态剖面的时间解析的流动结构。介绍了NPLS技术以及基于NPLS开发的密度场测量、雷诺应力测量和气动光学波前测量等方法,并回顾了这些技术在超声速边界层、超声速混合层、超声速压缩拐角、激波/边界层相互作用和光学头罩绕流等流动中的应用,清晰地再现了边界层、混合层、激波等典型流场结构及其时空演化特性。另外,为了模拟和研究高空大气条件下边界层自然转捩和超声速混合层的转捩特性,介绍了高超声速静风洞、超-超混合层风洞的设计技术以及层流化喷管的设计方法。     

Research on Auto-detection for Remainder Particles of Aerospace Relay Based on Wavelet Analysis

Aerospace relay is one kind of electronic components which is used widely in national defense system and aerospace system. The existence of remainder particles induces the reliability declining, which has become a severe problem in the development of aerospace relay. Traditional particle impact noise detection (PIND) method for remainder detection is ineffective for small particles, due to its low precision and involvement of subjective factors. An auto-detection method for PIND output signals is proposed in this paper, which is based on direct wavelet de-noising (DWD), cross-correlation analysis (CCA) and homo-filtering (HF), the method enhances the affectiv-ity of PIND test about the small particles. In the end, some practical PIND output signals are analysed, and the validity of this new method is proved.