摘要
为了探究贫油直喷(LDI)燃烧室中剪切旋流与火焰的正反馈作用及其诱导燃烧不稳定机理,通过大涡模拟(LES)结合相空间重构、模态分解分析方法研究了外激励作用下分层旋流火焰流场与火焰的动态响应。将流场的试验与LES时均结果进行对比,发现数值计算的速度分布与涡旋结构的大小、位置都和试验结果吻合较好。对LES采集信号与瞬时流场分析表明:燃烧室内压力与释热率脉动处于极限环振荡状态,速度脉动下回流区的收缩与扩张导致燃料和释热区发生周期性压缩与舒张,从而产生准周期释热率脉动。对LES提取的子午面数据进行模态分解,发现速度脉动和释热率脉动主要集中在射流区与剪切层处,均为进口速度激励导致的纵向脉动。
To study the feedback of shear swirl and flame and its induced combustion instability mechanism in the lean direct injection(LDI)combustor,the dynamic response of flow field and flame excited with external excitation was studied by large eddy simulation(LES)combined with phase space reconstruction and modal decomposition.Comparing the experimental results of the flow field with the time averaged results of LES,it was found that the velocity distribution of the numerical calculation and the size and position of the vortex structure were in good agreement with the experimental results.The analysis of LES acquisition signal and instantaneous flow field showed that the pressure and heat release pulsation were in the limit cycle oscillation state.The contraction and expansion of the recirculation zone under velocity pulsation led to the periodic compression and relaxation of the fuel and heat release zone,resulting in quasi-periodic heat release pulsation.The modal decomposition of the data on the meridian plane showed that the velocity and heat release pulsation were mainly concentrated in the shear layer and the jet region.Meanwhile,the main pulsation modes were all longitudinal pulsations excited by the inlet velocity.
作者
宋雷洋
姚倩
黄晓锋
袁丽
李建中
邓远灏
田世泽
SONG Leiyang;YAO Qian;HUANG Xiaofeng;YUAN Li;LI Jianzhong;DENG Yuanhao;TIAN Shize(Key Laboratory of Aero-engine Thermal Environment and Structure,Ministry of Industry and Information Technology,Nanjing University of Aeronautics and Astronautics,Nanjing 210016,China;Sichuan Gas Turbine Establishment,Aero Engine Corporation of China,Chengdu 610599,China;School of National Defense Engineering,the Army Engineering University of the Chinese People’s Liberation Army,Nanjing 210007,China)
出处
《航空动力学报》
EI
CAS
CSCD
北大核心
2024年第5期36-49,共14页
Journal of Aerospace Power
基金
产学研合作项目(HFZL2020CXY005)。
关键词
外激励
分层旋流
贫油直喷
大涡模拟
相空间重构
模态分解
excitation
stratified swirl
lean direct injection
large eddy simulation
phase space reconstruction
modal decomposition
