航空发动机烟雾排放的符合性验证方法研究

通过研究CCAR-34中烟雾排放的测试大纲,参考芝加哥公约附件16第二卷附录2和航空燃气涡轮发动机排气冒烟测量规范HB-6116-87,设计了烟雾排放测量试验的操作流程,包括取样测量系统的设计、取样测量步骤、试验数据处理。结合ICAO发动机排放数据库中CFM56-2B-1的发烟指数（SN）,验证其与烟雾排放标准的符合性,探索了发动机烟雾排放适航验证方法。     

TPA对低特征信号衬层性能的影响

为研制低特征信号衬层提供参考依据，选用了消烟剂ＴＰＡ，通过制作衬层试样，衬层的信号透过率力学性能和粘接性能的测试，以及对试验结果进行分析和讨论，发现ＴＰＡ的含量与料径变化对上述性能都存在的影响，并且呈献一定规律。     

含LLM-105的钝感微烟推进剂能量参数和燃烧特性

研究了2,6-二氨基-3,5-二硝基吡嗪-1-氧化物(LLM-105)与改性双基推进剂主要组分的相容性以及含LLM-105的钝感微烟推进剂的能量参数和燃烧特性.结果表明,LLM-105与改性双基推进剂的主要组分具有良好的相容性;用LLM-105逐渐取代RDX,钝感微烟推进剂的理论比冲和等容爆热降低;含LLM-105的推...     

基于逆向设计的飞机货舱烟雾等效方法

在飞机货舱烟雾探测的适航符合性验证中,为尽可能降低验证试验风险,通常需要采用烟雾发生器产生的模拟烟雾来代替真实火灾烟雾进行飞行试验,但研究表明两种烟雾在造成烟雾探测器响应时间方面存在较大差异,必须通过改变烟雾发生器边界条件来实现与真实火灾烟雾的等效,然而,通过传统"试错法"寻找能够实现两种烟雾等效的边界条件将耗费大量时间资源。采用逆向设计的方法,首先在火灾动力学模拟（FDS）软件中分别建立烟雾发生器模拟烟雾与真实火灾烟雾数值模型,并在Isight优化软件中将FDS进行集成,通过构建使两种烟雾等效的目标函数,采用多岛遗传算法（MIGA）对烟雾发生器边界条件进行一次性逆向求解,从而避免了传统"试错法"造成的资源浪费。对逆向计算的结果进行了试验验证,逆向求解得到的边界条件能实现烟雾发生器模拟烟雾与真实火灾烟雾的等效,该结果可直接指导飞机货舱烟雾探测的适航符合性验证工作。     

Reduced meteoric smoke particle density at the summer pole – Implications for mesospheric ice particle nucleation

Noctilucent clouds (NLC) and polar mesospheric summer echoes (PMSE) are phenomena that occur in the summertime polar regions due to the presence of ice particles around the mesopause. That ice particles are able to form in a region with such low water vapour concentration as the mesopause is noteworthy. Even though the summer mesopause is the coldest region on Earth, temperatures are generally not low enough for homogeneous nucleation to occur, which necessitates the presence of pre-existing condensation nuclei. The nature of these nuclei has long puzzled the scientific community and many candidates have been suggested, such as particles of meteoric origin, ion clusters, sodium bi-carbonate, sulfate aerosols and soot particles. Out of these the so-called “smoke particles”, i.e. particles re-condensed from ablated meteoritic material, have long been considered the most likely. Generally, it has been believed that these particles exist in numbers of the order of thousands per cubic centimetre at the mesopause. This belief is based on 1-dimensional studies of meteoric material. A recent 2-dimensional model study, which includes the atmospheric circulation from summer to winter pole however, suggests much lower number densities at the summer mesopause. We here investigate the implications of low number densities for the formation of ice particles. We find that even though resulting ice particle distribution may produce typical NLC brightness, the number density of ice particles is not consistent with what is expected for NLC and PMSE. In particular, it is much lower than the ice particle concentration (>1000 cm⁻³) typically expected to explain the “electron bite-outs” that are frequently observed in the vicinity of PMSE’s. We therefore re-examine the assumptions and parameters that determine the smoke distribution. We show that even though the number of condensation nuclei at the polar summer mesopause can be increased within the uncertainties, the results in most scenarios remain insufficient. We show that charged particles, perhaps in combination with significant deviations from the mean mesospheric state, may be necessary for condensation of ice particles in the polar summer mesosphere. Hence, we raise the question whether the conventional ideas of nucleation on meteoric smoke, which are used in current mesospheric ice models, are correct.     

BP神经网络在火灾烟气危害性分级中的应用

建筑物发生火灾时，燃烧产生的高热和有毒、有害气体对人构成很大威胁。本文利用ＢＰ神经网络对火灾烟气危害性进行分级，介绍了神经网络模型的结构、学习过程和算法。实例计算表明：利用神经网络对烟气危害性分级是合理可行的，具有一定的实用价值。     

少烟高固体含量丁羟推进剂配方研究

通过理论计算和初步实验，证实少烟高固体含量丁羟推进剂是实用的。研究表明，铝粉含量对Ｉ＾０ｓｐ、燃气中Ａｌ２Ｏ３含量、ρ有显著影响，降低铝粉含量，比冲大幅度下降；ＲＤＸ代替部分ＡＰ，烯气中ＨＣ１、Ｈ２Ｏ含量降低，但（ＣＯ＋Ｈ２）含量增加，增加了燃气的二次火焰，低铝粉配方中，ＲＤＸ不能提高比冲；增加固体含量，能明显提高比冲和密度，是提高能量特性的有效途径；提高压强，比冲增加，燃气中Ｈ２Ｏ％和ＣＯ＋Ｈ２     

高压燃烧室的冒烟测量

在单头部主室件上进行的高温高压试验研究中，冒烟是研究发动机排放特性的一个参数。为了避免直接加热器所产生的燃气中的冒烟对主燃烧室冒烟测量带来的误差，该冒烟测量是在主燃烧室常温下进行的。最后根据试验数据校验与之类似燃烧室冒烟经验模型。经验模型根据GE公司的F101发动机燃烧室的冒烟经验模型得出SN8＝2．62＋0．853[ln(Ss）]。在压力范围为2．0－3．2MPa之内，试验数据与经验模型的计算结果吻合较好。但是试验研究发现，燃烧室进口空气压力增高，冒烟显增加。因而，该模型不能应用到3．8MPa以上的高压力范围。     

武汉体育中心体育场内场风环境定量测量

采用一种新型水平速度传感器,测量体育场内场水平风速,同时用烟线示踪粒子显示方法,同步辨别了传感器所处位置的风向。通过图像处理,获得体育场在不同的风向条件下内场各测点的水平速度矢量,并给出了变化的速度场水平方向瞬时流线,对该体育场在风作用下内场风场的品质作出预报。     

前货舱防烟渗漏改装中的逻辑分析

对比分析了波音737NG飞机进行前货舱防烟渗漏的电气改装前后所加装的工作逻辑电路,系统阐述了波音737NG飞机在前货舱烟雾渗漏方面所做的改进,以及在改装工作中可能会遇到的故障。