摘要
为揭示旋流强度对中心分级燃烧室高温区的影响作用,采用大涡模拟(LES)研究了不同旋流数下的高温区形成、演化和耗散过程及其对燃烧室出口温度分布的影响机制。大涡模拟中的燃烧模型采用火焰面生成流型(FGM)方法,并基于粒子示踪测速(PIV)和OH组分平面激光诱导荧光(OH-PLIF)进行实验验证。结果表明,强旋流使燃烧室出口温度概率密度分布(PDF)峰值减小,出口温度分布系数(OTDF)和热斑面积比(HAR)也降低。同时,火焰扩张角增大,火焰更为紧缩,中心回流区也沿径向扩张,使高温产物回流加强、驻留时间更长。此外,剪切层涡被强化,径向对流作用增大,使级间混合加强并降低温度梯度。在燃烧室下游,高旋流数也强化了低温流体对高温微团的掺混和冷却耗散作用,避免了高温微团直接迁移到燃烧室出口。基于以上结果,得出高旋流数可显著提升出口温度分布均匀性的结论,并揭示了强旋流在主燃区及其下游抑制高温区的主要机制。
In order to clarify influence of swirl intensity on the high-temperature zone of a centrally-staged combustor,the formation,evolution and dissipation of high-temperature zone,as well as the effects on the exit temperature distribution,were studied under different swirl number using the large eddy simulation(LES).The combustion model of flamelet-generated manifold(FGM)was adopted,and the modelling was experimentally validated against the particle imaging velocimetry(PIV)and planar laser-induced fluorescence of OH(OHPLIF).Results show that the peak probability density function(PDF)of the exit temperature distribution is lower with stronger swirl intensity,and the outlet temperature distribution factor(OTDF)and hot streak area ratio(HAR)are all reduced.Meanwhile,the flame open angle increases,the flame is more compact,and the primary recirculation zone expands radially,which recirculate and reserve the hot products longer.Moreover,the shear layer vortices are enhanced and radial convection is intensified which reinforce the mixing between the pilot and main stages and reduce the temperature gradient.Downstream of the combustor,the large swirl number also promotes the mixing,cooling and dissipation of the high-temperature zone by the colder flow,avoiding direct migration of the high-temperature parcels towards the burner outlet.It is concluded that the large swirl number can obviously improve the uniformity of the exit temperature distribution;meanwhile,within and downstream of the primary combustion zone,the major mechanisms to mitigate the high-temperature zone by the strong swirling flow were revealed.
作者
张玮杰
李德立
金武
王金华
黄佐华
ZHANG Weijie;LI Deli;JIN Wu;WANG Jinhua;HUANG Zuohua(State Key Laboratory of Multiphase Flow in Power Engineering,Xi’an Jiaotong University,Xi’an 710049,China;College of Energy and Power Engineering,Nanjing University of Aeronautics and Astronautics,Nanjing 210016,China)
出处
《推进技术》
北大核心
2025年第5期184-195,共12页
Journal of Propulsion Technology
基金
国家自然科学基金(52206169,52276118)。
关键词
中心分级燃烧室
旋流燃烧
出口温度分布
大涡模拟
旋流混合
Centrally-staged combustor
Swirling combustion
Outlet temperature distribution
Largeeddy simulation
Swirling mixing
作者简介
通讯作者:张玮杰,博士,助理教授,研究领域为发动机湍流燃烧。E-mail:wjzhang@xjtu.edu.cn。
