POD analysis of the dynamic structures of a low swirl number precessing jet

FU Hao; HE Chuangxin; LIU Yingzheng

doi:10.11729/syltlx20210006

Volume 35 Issue 4

Aug. 2021

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FU H，HE C X，LIU Y Z. POD analysis of the dynamic structures of a low swirl number precessing jet[J]. Journal of Experiments in Fluid Mechanics, 2021，35（4）：1-9. doi: 10.11729/syltlx20210006

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POD analysis of the dynamic structures of a low swirl number precessing jet

doi: 10.11729/syltlx20210006

FU Hao^{1, 2},
HE Chuangxin^{1, 2
,
,},
LIU Yingzheng^{1, 2}

1.
Turbomachinery Research Institute, School of Mechanical Engineering, Shanghai Jiao Tong University, Shanghai　200240, China
2.
Institute of Gas Turbine, Shanghai Jiao Tong University, Shanghai　200240, China

Received Date: 2021-01-20
Rev Recd Date: 2021-03-02

Available Online: 2021-08-26

Publish Date: 2021-08-31

Abstract

Abstract

The flow field of a low swirl number precessing jet at Reynolds number Re = 4.5×10⁴ is measured using particle image velocimetry （PIV） and the dynamics of the large-scale flow structures are examined further using the proper orthogonal decomposition（POD） analysis. The spatial modes obtained by POD and the fluctuating velocity field obtained by POD reconstruction at three swirl numbers, i.e., S = 0, 0.26 and 0.41, are compared and analyzed. The POD results show that the precession induces an alternating flow, switching between outflow from one side of the chamber along the chamber wall and inflow from another side. When the precession occurs, the vortex structures in the upstream shear layers have not broken down completely. They will develop downstream until approaching the starting point of the precession and then deflect with the mainstream. However, the large-scale structures in the downstream shear layers are completely destroyed. As the swirl number increases, the region affected by the precession moves upstream, and the orderly vortex structures in the shear layers break down.
- POD analysis,
- low swirl number,
- precessing jet,
- dynamic structures

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References(20)

References

[1]	NATHAN G J, MANIAS C G. The role of process and flame interaction in reducing NO_x emissions[C]//Proceedings of the Institute of Energy's Second International Conference on Combustion & Emissions Control. 1995. doi: 10.1016/b978-0-902597-49-5.50032-9
[2]	NEWBOLD G J R,NATHAN G J,NOBES D S,et al. Measurement and prediction of NO_x emissions from unconfined propane flames from turbulent-jet, bluff-body, swirl, and precessing jet burners[J]. Proceedings of the Combustion Institute,2000,28(1):481-487. doi: 10.1016/S0082-0784(00)80246-5
[3]	DENG Y B,WU H W,SU F M. Combustion and exhaust emission characteristics of low swirl injector[J]. Applied Thermal Engineer-ing,2017,110:171-180. doi: 10.1016/j.applthermaleng.2016.08.169
[4]	COLORADO A,MCDONELL V. Emissions and stability performance of a low-swirl burner operated on simulated biogas fuels in a boiler environment[J]. Applied Thermal Engineering,2018,130:1507-1519. doi: 10.1016/j.applthermaleng.2017.11.047
[5]	TONG Y H,YU S B,LIU X,et al. Experimental study on dynamics of a confined low swirl partially premixed methane-hydrogen-air flame[J]. International Journal of Hydrogen Energy,2017,42(44):27400-27415. doi: 10.1016/j.ijhydene.2017.09.066
[6]	NATHAN G J,HILL S J,LUXTON R E. An axisymmetric ‘fluidic’ nozzle to generate jet precession[J]. Journal of Fluid Mechanics,1998,370:347-380. doi: 10.1017/s002211209800202x
[7]	LUXTON R E, NATHAN G J. Mixing fluids: Australian, PCT/AU88/0014[P]. 1987.
[8]	NATHAN G J,MI J,ALWAHABI Z T,et al. Impacts of a jet's exit flow pattern on mixing and combustion performance[J]. Progress in Energy and Combustion Science,2006,32(5-6):496-538. doi: 10.1016/j.pecs.2006.07.002
[9]	MADEJ A M,BABAZADEH H,NOBES D S. The effect of chamber length and Reynolds number on jet precession[J]. Experiments in Fluids,2011,51(6):1623-1643. doi: 10.1007/s00348-011-1177-0
[10]	WONG C Y,LANSPEARY P V,NATHAN G J,et al. Phase-averaged velocity in a fluidic precessing jet nozzle and in its near external field[J]. Experimental Thermal and Fluid Science,2003,27(5):515-524. doi: 10.1016/S0894-1777(02)00265-0
[11]	CAFIERO G,CEGLIA G,DISCETTI S,et al. On the three-dimensional precessing jet flow past a sudden expansion[J]. Experi-ments in Fluids,2014,55(2):1-13. doi: 10.1007/s00348-014-1677-9
[12]	CEGLIA G,CAFIERO G,ASTARITA T. Experimental investigation on the three-dimensional organization of the flow structures in pre-cessing jets by tomographic PIV[J]. Experimental Thermal and Fluid Science,2017,89:166-180. doi: 10.1016/j.expthermflusci.2017.08.008
[13]	CHAN C K, LAU K S, CHIN W K, et al. Freely propagating open premixed turbulent flames stabilized by swirl[C]//Proc of the Sym-posium (International) on Combustion. 1992. doi: 10.1016/S0082-0784(06)80065-2.
[14]	CHENG R K. Velocity and scalar characteristics of premixed turbulent flames stabilized by weak swirl[J]. Combustion and Flame,1995,101(1-2):1-14. doi: 10.1016/0010-2180(94)00196-Y
[15]	DELLENBACK P A,METZGER D E,NEITZEL G P. Measurements in turbulent swirling flow through an abrupt axisymmetric expan-sion[J]. AIAA Journal,1988,26(6):669-681. doi: 10.2514/3.9952
[16]	MARKOVICH D M,ABDURAKIPOV S S,CHIKISHEV L M,et al. Comparative analysis of low- and high-swirl confined flames and jets by proper orthogonal and dynamic mode decompositions[J]. Physics of Fluids,2014,26(6):2893-2900. doi: 10.1063/1.4884915
[17]	付豪,何创新,刘应征. 低旋流数旋进射流流动特性的PIV实验研究[J]. 实验流体力学,2021,35(3):39-45. doi: 10.11729/syltlx20200129 FU H,HE C X,LIU Y Z. PIV experimental study on flow characteri-stics of a low swirl number precessing jet[J]. Journal of Experi-ments in Fluid Mechanics,2021,35(3):39-45. doi: 10.11729/syltlx20200129
[18]	HE C X,GAN L,LIU Y Z. The formation and evolution of turbulent swirling vortex rings generated by axial swirlers[J]. Flow, Turbulence and Combustion,2020,104(4):795-816. doi: 10.1007/s10494-019-00076-2
[19]	SIROVICH L. Turbulence and the dynamics of coherent structures. II. Symmetries and transformations[J]. Quarterly of Applied Mathe-matics,1987,45(3):573-582. doi: 10.1090/qam/910463
[20]	SEMERARO O,BELLANI G,LUNDELL F. Analysis of time-resolved PIV measurements of a confined turbulent jet using POD and Koopman modes[J]. Experiments in Fluids,2012,53(5):1203-1220. doi: 10.1007/s00348-012-1354-9