Effects of acoustic excitation on the dynamics of centrically⁃staged swirling stratified flames under different air split ratios
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摘要:
采用高速摄像拍摄火焰化学自发光和本征正交分解(POD)法研究了多激励频率下中心分级旋流分层火焰的宏观结构和动力学特性。结果表明:随着气量分配比的增加,火焰宏观结构逐渐沿径向方向扩张,火焰分层现象变得更加明显。激励频率的变化对火焰宏观结构的影响较小。POD分析结果表明:外激频率为200 Hz时火焰脉动最明显。随着主燃级气量占比的增加,释热脉动在激励的作用下沿轴向方向减弱,在径向上出现极值交替且振荡变强。
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关键词:
- 燃烧不稳定性 /
- 中心分级燃烧室 /
- 旋流火焰 /
- 火焰动力学 /
- 本征正交分解(POD)
Abstract:Macrostructures and dynamic characteristics of concentrically‑staged swirling stratified flames under multiple excitation frequencies were studied using high⁃speed CH* chemiluminescence and proper orthogonal decomposition (POD).Results showed that the flame expanded radially with more pronounced stratification as air split ratio increased,whereas the excitation frequency played an insignificant role.POD analysis revealed that among the conducted external excitation cases,the most intense flame oscillations were observed at the excitation frequency of 200 Hz.With the increase of main stage air allocation,the heat release oscillation decreased along the axial direction.On the radial direction,however,local minima and maxima were alternately observed with stronger oscillations.
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表 表 1 实验工况参数表
Table 表 1. Experimental conditions
空气总流量/(g/s) 主燃级空气流量/(g/s) 预燃级空气流量/(g/s) 总当量比 分层比 主燃级当量比 主燃级甲烷流量/(g/s) 预燃级甲烷流量/(g/s) 1 0.4 0.6 0.95 1 0.95 0.022 0.033 1 0.5 0.5 0.95 1 0.95 0.028 0.028 1 0.6 0.4 0.95 1 0.95 0.033 0.022 -
[1] DUROX D,SCHULLER T,NOIRAY N,et al.Experimental analysis of nonlinear flame transfer functions for different flame geometries[J].Proceedings of the Combustion Institute,2009,32(1):1391⁃1398. [2] 刘宗宽,刘昌文,卫海桥,等.湍流强度对火焰传播影响的大涡模拟研究[J].车用发动机,2019,37(4):79⁃87.LIU Zongkuan,LIU Changwen,WEI Haiqiao,et al.Effect of turbulence intensity on flame propagation based on large eddy simulation[J].Vehicle Engine,2019,37(4):79⁃87.(in Chinese) [3] PALIES P,DUROX D,SCHULLER T,et al.The combined dynamics of swirler and turbulent premixed swirling flames[J].Combustion and Flame,2010,157(9):1698⁃1717. [4] ALTAY H M ,SPETH R L ,HUDGINS D E,et al.Flame⁃vortex interaction driven combustion dynamics in a backward⁃facing step combustor[J].Combustion and Flame,2009,156(5):1111⁃1125. [5] KIM K M,YOON J,PARK S,et al.Effects of unstable flame structure and recirculation zones in a swirl⁃stabilized dump combustor[J].Applied Thermal Engineering,2013,58(1/2):125⁃135. [6] DHANUKA S K,TEMME J E,DRISCOLL J F,et al.Vortex⁃shedding and mixing layer effects on periodic flashback in a lean premixed prevaporized gas turbine combustor[J].Proceedings of the Combustion Institute,2008,32(2):2901⁃2908. [7] 张俊,涂晓波,陈爽,等.贫燃预混旋流火焰PIV和OH⁃PLIF[J].航空动力学报,2020,35(10):2046⁃2055.ZHANG Jun,TU Xiaobo,CHEN Shuang,et al.Instantaneous and simultaneous PIV and OH⁃PLIF measurement for lean premixed swirl flame[J].Journal of Aerospace Power,2020,35(10):2046⁃2055.(in Chinese) [8] TAAMALLAH S,SHANBHOGUE S J,GHONIEM A F.Turbulent flame stabilization modes in premixed swirl combustion:physical mechanism and Karlovitz number⁃based criterion[J].Combustion and Flame,2016,166:19⁃33. [9] 魏星.贫燃预混燃烧火焰形态与流场研究[D].大连:大连理工大学,2017.WEI Xing.Flame shape and flow field research of lean premixed combustion[D].Dalian:Dalian University of Technology,2017.(in Chinese) [10] CHEN H,REUSS D L,HUNG D L S,et al.A practical guide for using proper orthogonal decomposition in engine research[J].International Journal of Engine Research,2013,14(4):307⁃319. [11] 谢法,黄勇,苗辉,等.气量分配对双轴向旋流器燃烧室贫熄性能影响[J].北京航空航天大学学报,2011,37(11):1456⁃1460.XIE Fa,HUANG Yong,MIAO Hui,et al.Effects of airflow split and primary holes arrangement on lean blowout limits of combustor with dual⁃axial swirlers[J].Journal of Beijing University of Aeronautics and Astronautics,2011,37(11):1456⁃1460.(in Chinese) [12] 谢法,黄勇,苗辉,等.气量分配对轴径向旋流杯燃烧室贫熄边界的影响[J].航空动力学报,2011,26(8):1756⁃1760.XIE Fa,HUANG Yong,MIAO Hui,et al.Effects of airflow split and primary holes arrangement on the lean blowout limits of a combustor with axial⁃radial swirl cup[J].Journal of Aerospace Power,2011,26(8):1756⁃1760.(in Chinese) [13] WEI Xiao,YONG Huang.Lean blowout limits of a gas turbine combustor operated with aviation fuel and methane[J].Heat Mass Transfer,2016,52(5):1015⁃1024. [14] 姜磊,孔文俊.双级反向旋流器气量分配对燃烧室性能的影响[J].热能动力工程,2018,33(3):50⁃56.JIANG Lei,KONG Wenjun.Effects of air split of dual⁃stage counter rotating swirlers on the performance of combustor[J].Journal of Engineering for Thermal Energy and Power,2018,33(3):50⁃56.(in Chinese) [15] 付镇柏,林宇震,张弛,等.中心分级燃烧室预燃级燃烧性能实验[J].航空动力学报,2015,30(1):46⁃52FU Zhenbo,LIN Yuzhen,ZHANG Chi,et al.Experiment of combustion performance of internally⁃staged combustor pilot stage[J].Journal of Aerospace Power,2015,30(1):46⁃52.(in Chinese) [16] HAN X,LAERA D,MORGANS A S,et al.Flame macrostructures and thermoacoustic instabilities in stratified swirling flames[J].Proceedings of the combustion institute, 2018,37(4):5377⁃5384. [17] HAN X,LAERA D,YANG D,et al.Flame interactions in a stratified swirl burner:flame stabilization,combustion instabilities and beating oscillations[J].Combustion and Flame,2019,212:500⁃509. [18] 张弛,周宇晨,韩啸,等.同心旋流分层预混火焰的动力学模态分析[J].推进技术,2020,41(3):595⁃604.ZHANG Chi,ZHOU Yuchen,HAN Xiao,et al.Dynamic mode analysis on internally⁃staged⁃swirling stratified premixed flame[J].Journal of Propulsion Technology,2020,41(3):595⁃604.(in Chinese) [19] 苏童.外激速度扰动条件下分层旋流火焰的动态响应[D].北京:北京航空航天大学,2021.SU Tong.Response of stratified swirl⁃stabilized flame to the forced⁃excited velocity disturbances[D].Beijing:Beihang University,2021.(in Chinese) [20] PALIES P,DUROX D,SCHULLER T,et al.The combined dynamics of swirler and turbulent premixed swirling flames[J].Combustion and Flame,2010,157(9):1698⁃1717. [21] DASCH C J.One⁃dimensional tomography:a comparison of Abel,onion⁃peeling,and filtered backprojection methods[J].Applied Optics,1992,31(8):1146⁃1152. [22] MA K,YU X,ZHAO X,et al.Response of lean premixed swirl tubular flame to acoustic perturbations[J].Experimental Thermal and Fluid Science,2020,119:110199.1⁃110199.10. [23] CHARALAMBIDES A G,SAHU S,HARDALUPAS Y,et al.Evaluation of homogeneous charge compression ignition (HCCI) autoignition development through chemiluminescence imaging and proper orthogonal decomposition[J].Applied Energy,2018,210:288⁃302. -