摘要
为分析超声速燃烧室中的火焰振荡特性,以氢气为燃料,采用高速化学发光测量对两种当量比下凹腔燃烧室中的火焰发光图像进行了采集,时间重复频率为100 kHz。通过对所采集的图像进行统计学分析,包括时均分析、标准差分析、本征正交分解(POD)分析、剪切层火焰面速度振荡分析,研究了凹腔内燃烧振荡的宏观模式及瞬态特性。结果表明,当量比为0.3和当量比为0.2的工况,火焰均稳定在凹腔内部,且火焰稳定位置和表面积都极为相似,当量比为0.3时在超声速主流区发现明显的火焰信号,分析是由较大的燃料射流形成的弓形激波导致的。POD结果表明,两组工况下凹腔燃烧室中火焰的振荡以凹腔内部流动方向的振荡为主,同时复合了凹腔内部各个回流区与剪切层相互作用的振荡。剪切层的火焰面振荡速度表明,低当量比下火焰在剪切层附近的振荡更为剧烈,平均的振荡速度接近高当量比工况的2倍。
To analyze the oscillation behavior of the flame in a supersonic combustor fueled with hydrogen,high⁃speed chemilu⁃minescence images were recorded under two different equivalence ratios(Φ).A series of statistical analysis were performed,inclu⁃ding the time⁃averaging of the images,the RMS variation,the proper orthogonal decomposition(POD)and the oscillation of the flame edge speed at the shear layer,to study the overall and transient behaviors of the flame instabilities.The results show that the flame is stabilized in the cavity in both fuel lean and fuel rich conditions,and the anchor position and flame surface area are similar in both cases.In fuel rich case,the flame was observed also in the main supersonic flow region which is attributed to the bow shock formed by the fuel jet.Via POD analysis,the main flame oscillation modes in the cavity combustor are the alternative oscillation a⁃long the flow direction and the alternative oscillation between the shear layer and the recirculating zone in the cavity.The fluctuation of the flame brush edge speed under the condition ofΦ=0.2 is 2 times larger than that ofΦ=0.3.
作者
赵小存
雷庆春
陈力
陈爽
田野
范玮
ZHAO Xiaocun;LEI Qingchun;CHEN Li;CHEN Shuang;TIAN Ye;FAN Wei(School of Power and Energy,Northwestern Polytechnical University,Xi'an710129,China;China Aerodynamics Research and Development Center,Mianyang621000,China)
出处
《固体火箭技术》
CAS
CSCD
北大核心
2021年第3期297-303,共7页
Journal of Solid Rocket Technology
基金
国家自然科学基金(91741108)。
关键词
超燃冲压发动机
超声速燃烧
高速化学自发光
本征正交分解
scramjet
supersonic combustion
high⁃speed chemiluminescence imaging
proper orthogonal decomposition
