复合式收扩套筒空气雾化喷嘴燃烧室点火研究

复合式收扩套筒空气雾化喷嘴中, 副油路是一个单油路离心喷嘴, 主油路采用双旋流空气雾化, 喷嘴是直射式.在点火研究中, 只是单油路离心喷嘴工作.实验用的燃烧室是一个单头部矩形燃烧室, 在燃烧室进口温度为常温, 进口压力为常压, 燃烧室压力降0.9%9.0%的试验条件下研究了复合式空气雾化喷嘴燃烧室的点火性能.在同样条件下, 研究了复合式空气雾化喷嘴的雾化性能并总结了经验关系.分析了影响点火的主要因素, 通过整理雾化数据, 以Lefebvre点火模型为基础, 总结了该类燃烧室点火经验关系.      

Development of a micro gas turbine combustor with T-type vaporizers

The study includes the experimental investigation of the evaporation performance of T-type vaporizer,mainly studied the relationship of the inlet air temperature and vaporizer wall temperature with the evaporation ratio.Then,it studied the LBO(lean blow out) and combustion efficiency of the micro aero-engine combustor with T-type vaporizer on the normal pressure test rig.The inlet air condition is environmental pressure and temperature.The gas analysis method is used to study the combustion efficiency,and the inlet air temperature is 300 K,400 K and 500 K.It could be concluded that the evaporation performance is improved with the increasing of the inlet air temperature and vaporizer wall temperature;the average LBO is 0.003;the combustion efficiency rises with the inlet air temperature,and it remain constant when the fuel/air ratio changed in the range from 0.008 to 0.02.The vaporization ratio is the key factor to determine the combustion performance.      

基于伴随非等温射流理论的缝槽气膜冷却模型

在伴随非等温射流基础上发展了一种适用于缝槽气膜冷却绝热温比预估的数学模型.通过合理假设推导出二维壁面射流混合层核心温度分布规律,将其作为气膜绝热壁温,并考虑缝槽几何特征参数和气膜吹风比对冷却效率的影响,得到绝热温比计算公式.用试验数据对该预估模型进行拟合分析,得到了与试验数据拟合精度在±8%以内的半经验预估模型,证明该模型的可行性和应用潜力,并需要更多的试验数据对其进行验证和改进.      

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.     

速度脉动下分层旋流火焰动态传播结构提取

为了深刻理解分层旋流火焰的动态结构,开展了分层旋流火焰动态的模态分析和参数化研究.实验在BASIS(北京航空航天大学发展的具有台阶隔离段的独立分层旋流燃烧器)上开展,以甲烷为燃料预混燃烧,使用高速摄像捕捉了速度脉动下的CH*化学发光信号动态图像.利用传统的本征正交分解(POD)和重定向POD分析了火焰动态特性,并利用重...     

基于随机粒子追踪方法的环形燃烧室点火动态模拟

为了深入研究低排放燃烧室点火联焰规律,在全新的环形模型燃烧室中开展了点火模拟和试验研究。点火模拟采用随机粒子追踪方法,能够基于时均冷态流场的仿真结果快速模拟火焰传播过程。环形燃烧室包含16个中心分级旋流器,仅向预燃级通入丙烷,用于模拟航空发动机低排放燃烧室点火状态下的空气燃油分级。试验采用PIV技术测量3个头部区域流场,利用高速相机拍摄火焰CH*/C2*基团化学发光信号。对多个流量和当量比条件下的联焰过程、联焰时间和传焰速率进行了分析,试验和模拟的结果均表明：环形燃烧室内火焰双向传播,燃烧室内外环流速度差异导致了双向火焰传播速度差,传焰速率随燃烧室湍流速度和当量比的增加而增加。点火模型很好地捕捉了环形燃烧室点火动态,所得传焰速率也符合湍流火焰传播规律,表明该模型具有较强预测能力。     

短螺旋型燃烧室旋流结构及气动边界发展规律数值模拟研究

短螺旋型燃烧室的头部轴线沿发动机周向与发动机轴线偏转一定角度,可以在保证燃烧效率不变的条件下有效缩短燃烧室轴向长度。短螺旋型燃烧室流场的最大特点是旋流流动单侧受限。为了研究头部安装角α变化对燃烧室旋流流动特性的影响,基于数值方法对短螺旋型燃烧室进行了计算分析。结果表明:随着α变化,旋流器下游旋涡依次出现对称环状、马蹄状、环状结构;随着α增加,气动边界逐渐出现并抑制旋流的周向扩张,导致流场出现不同的旋涡结构;不同α下的切向角动量随轴向距离增加而衰减,但α为35°和45°时,气动边界在非受限侧出现并对旋流产生约束,角动量衰减变慢;当α为0°,15°,35°,45°时,燃油液滴依次集中分布在旋流器下游两旋涡边缘、侧壁面和头部端壁、非受限旋涡边缘。本文研究了不同α下的旋涡结构及气动边界沿轴向的演化过程,为短螺旋型燃烧室进一步的设计与优化提供基础。     

侧壁有出流孔的通道流场实验研究

用五孔探针对侧壁开有出流孔的通道流场进行了详细测量，着重研究出流孔上、下游截面内的流动规律,分析了错排孔对通道流场的影响。实验发现出流孔上游各截面内的流动沿流向呈加速趋势，其下游截面的流速先急剧减缓，然后逐渐加速直至下一出流。距孔最近的上游截面内气流明显向孔偏转，由于惯性作用，孔下游各截面内的二次流仍很显著。     

航空发动机主燃烧室稳定工作范围研究

应用火焰传播理论、二维两相紊流燃烧的k-ε模型、EBU-Arrhen ius模型、颗粒群轨道模型和AD INA软件,计算出了某型在研航空发动机在不同飞行状态下的主燃烧室贫油熄火时的流场、温度场和压力场;计算值与试验结果比较吻合,证实了数值模拟的合理性和可行性。     

基于CATIA的机床夹具元件快速造型方法

介绍了基于CATIA的CAA架构对实体进行参数化建模的方法,以一个航空夹具设计为实例,开发了基于CAA及零件特征的参数化航空夹具设计模块,为基于CATIA的航空夹具元件快速造型做了技术方法的探索.