喷嘴布局对钝体非预混火焰响应特性影响的试验研究
Experimental study on effects of nozzle layout on response of bluff-body non-premixed flames
赵妍 1刘勇 1赵航 1张祥1
作者信息
- 1. 南京航空航天大学 能源与动力学院,南京 210016
- 折叠
摘要
航空发动机加力燃烧室由于能量密度大、进口速度大、进口温度高,燃料和空气掺混不均匀等,易发生燃烧不稳定现象.加力燃烧室为多喷嘴结构,喷嘴布局会影响燃烧室内的释热率分布,进而影响火焰响应.以模型加力燃烧室为研究对象,对不同喷嘴数量和喷嘴直径的钝体非预混火焰的释热率响应特性进行研究.利用扬声器对火焰施加声激励,通过双麦克风法测量速度脉动,光电倍增管结合CH*滤光片测量释热率脉动.研究表明,喷嘴布局的改变对燃烧室内的释热率分布会产生显著影响,火焰传递函数(FTF)增益呈现典型的双峰特征.随着喷嘴数量增加,增益峰值先减小后增大,增益峰值对应的频率有向高频移动的趋势,系统时滞并未发生明显变化;随着喷嘴直径增加,FTF增益先减小后增大,系统时滞明显增大.
Abstract
Due to the high energy density,inlet velocity and temperature,and uneven mixing of fuel and air,the aero-engine afterburner is prone to combustion instability.The afterburner features a multi-nozzle configuration,where the nozzle arrangement can influence the heat release rate distribution within the combustion chamber,thereby affecting flame response.A model afterburner was taken as the research object to study the heat release rate response characteristics of bluff-body non-premixed flames with different nozzle numbers and nozzle diameters.Acoustic excitation was applied to the flame using two loudspeakers,and the velocity fluctuation was measured using the two-microphone method.Heat release rate fluctuation was measured using a photomultiplier tube combined with the CH*filter.The experimental results show that the change of nozzle layout has a significant effect on the heat release distribution within the combustion chamber.The flame transfer function(FTF)gain shows a typical double-peak feature.As the number of nozzles increases,the peak gain initially decreases and then increases.The frequency corresponding to the peak has a tendency to move to a high frequency.However,the system time delay remains largely unchanged.With the increase of nozzle diameter,the FTF gain initially decreases and then increases,while the system time delay increases.
关键词
航空发动机/加力燃烧室/燃烧不稳定/钝体火焰稳定器/喷嘴布局/火焰响应/火焰传递函数Key words
aero-engine/afterburner/combustion instability/bluff-body flame stabilizer/nozzle layout/flame response/flame transfer function引用本文复制引用
基金项目
航空发动机及燃气轮机基础研究项目(J2022-III-0007-0016)
出版年
2024
NETL
NSTL
万方数据