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2026 Vol.31, Issue 3 Preview Page

Research Article

100% H2-Air Flame Behaviors in Coaxial Dual-swirl Injector

동축 이중선회 인젝터에서 100% 수소-공기 화염거동 분석

Junpyo Hong1
,
Hyunchang Lee1
,
Keeman Lee1†
홍 준표1
,
이 현창1
,
이 기만1†
1School of Mechanical and Aerospace Engineering/Center for Aerospace Engineering Research, Sunchon National University
1국립순천대학교 기계우주항공공학부/우주항공연구센터
*Corresponding Author
30 September 2026. pp. 35-46
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Abstract

This study experimentally investigated the effects of swirling direction on the flame structure and lift-off behavior of a pure hydrogen–air flame in a coaxial dual-swirl injector for gas-turbine applications. Hydrogen fuel and combustion air were supplied separately through a central nozzle and an outer annular nozzle, respectively. The thermal input was fixed at 5 kW, while the outer-air velocity was set to 10 and 20 m/s. The reaction-zone distributions and time-averaged velocity fields under co-swirling and counter- swirling conditions were characterized using 10 kHz high-speed OH-planar laser-induced fluorescence (OH-PLIF) and two-dimensional particle image velocimetry (2D-PIV). At an outer-air velocity of 10 m/s, an attached M-shaped flame consisting of outer and inner flames was observed. At 20 m/s, the outer flame detached from the nozzle and transitioned to a V-shaped lifted flame. Under the co-swirling condition, both the central recirculation zone (CRZ) and inner recirculation zone (IRZ) were formed, whereas only the CRZ was clearly identified under the counter-swirling condition. Under the lifted-flame condition, the CRZ extended upstream toward the nozzle tip for both swirling configurations. The increased outer-air velocity enhanced the axial momentum of the outer swirling flow and intensified the velocity gradients near the recirculation-zone boundary, while promoting the radial redistribution of the central hydrogen jet. These near-nozzle flow modifications were considered to increase the local velocity and aerodynamic strain near the inner-nozzle lip, thereby weakening flame stabilization and promoting flame lift-off.

Keywords
Dual-swirl injector
Swirling direction
Attached flame
Lift-off flame
References
1

S. Taamallah, K. Vogiatzaki, F.M. Alzahrani, E.M.A. Mokheimer, M.A. Habib, A.F. Ghoniem, Fuel flexibility, stability and emissions in premixed hydrogen-rich gas turbine combustion: Technology, fundamentals, and numerical simulations, Appl. Energy 154 (2015) 1020-1047.

10.1016/j.apenergy.2015.04.044
2

A.L. Sánchez, F.A. Williams, Recent advances in understanding of flammability characteristics of hydrogen, Prog. Energy Combust. Sci. 41 (2014) 1-55.

10.1016/j.pecs.2013.10.002
3

T. Lieuwen, V. McDonell, E. Petersen, D. Santavicca, Fuel flexibility influences on premixed combustor blowout, flashback, autoignition, and stability, J. Eng. Gas Turbines Power 130 (2008) 011506.

10.1115/1.2771243
4

Y. Huang, V. Yang, Dynamics and stability of lean- premixed swirl-stabilized combustion, Prog. Energy Combust. Sci. 35 (2009) 293-364.

10.1016/j.pecs.2009.01.002
5

S. Taamallah, S.J. Shanbhogue, A.F. Ghoniem, Turbulent flame stabilization modes in premixed swirl combustion: Physical mechanism and Karlovitz number-based criterion, Combust. Flame 166 (2016) 19-33.

10.1016/j.combustflame.2015.12.007
6

S. Hong, S.J. Shanbhogue, A.F. Ghoniem, Impact of fuel composition on the recirculation zone structure and its role in lean premixed flame anchoring, Proc. Combust. Inst. 35 (2015) 1493-1500.

10.1016/j.proci.2014.05.150
7

Q. An, A.M. Steinberg, The role of strain rate, local extinction, and hydrodynamic instability on transition between attached and lifted swirl flames, Combust. Flame 199 (2019) 267-278.

10.1016/j.combustflame.2018.10.029
8

F. Vashahi, J. Lee, On the emerging flow from a dual-axial counter-rotating swirler; LES simulation and spectral transition, Appl. Therm. Eng. 129 (2018) 646-656.

10.1016/j.applthermaleng.2017.10.058
9

Y. Sung, G. Choi, Non-intrusive optical diagnostics of co- and counter-swirling flames in a dual swirl pulverized coal combustion burner, Fuel 174 (2016) 76-88.

10.1016/j.fuel.2016.01.011
10

J. Li, T. Xia, B. Sun, F. Meng, W. Song, X. Lv, Experimental study of rotating direction for dual- axial swirlers on the flow field and combustion characteristics of aero-engine combustor, Case Stud. Therm. Eng. 61 (2024) 105135.

10.1016/j.csite.2024.105135
11

A. Degenève, R. Vicquelin, C. Mirat, J. Caudal, T. Schuller, Impact of co- and counter-swirl on flow recirculation and liftoff of non-premixed oxy-flames above coaxial injectors, Proceedings of the Combustion Institute, 38 (2021) 5501-5508.

10.1016/j.proci.2020.06.279
12

S. Marragou, H. Magnes, A. Aniello, L. Selle, T. Poinsot, T. Schuller, Experimental analysis and theoretical lift-off criterion for H2/air flames stabilized on a dual swirl injector, Proc. Combust. Inst. 39 (2023) 4345-4354.

10.1016/j.proci.2022.07.255
13

A. Aniello, D. Laera, S. Marragou, H. Magnes, L. Selle, T. Schuller, T. Poinsot, Experimental and numerical investigation of two flame stabilization regimes observed in a dual swirl H2-air coaxial injector, Combust. Flame 249 (2023) 112595.

10.1016/j.combustflame.2022.112595
14

S. Marragou, H. Magnes, A. Aniello, T.F. Guiberti, L. Selle, T. Poinsot, T. Schuller, Modeling of H2/air flame stabilization regime above coaxial dual swirl injectors, Combust. Flame 255 (2023) 112908.

10.1016/j.combustflame.2023.112908
15

J. Jiang, X. Zhang, T. Yu, B. Sun, H. Zhou, Z. Ren, Structural impact on flame dynamics and mode transition in dual-swirl hydrogen flames, Aerosp. Sci. Technol. 162 (2025) 110206.

10.1016/j.ast.2025.110206
16

I. Kim, S.H. Cho, K. Lee, A.R. Masri, A comparative study of turbulent stratified flames with different pilot nozzle configuration in dual-swirl injector, Int. J. Hydrogen Energy 223 (2026) 154239.

10.1016/j.ijhydene.2026.154239
17

J. Kim, M. Jang, K. Lee, A.R. Masri, Experimental study of the beating behavior of thermoacoustic self-excited instabilities in dual swirl combustors, Exp. Therm. Fluid Sci. 105 (2019) 1-10.

10.1016/j.expthermflusci.2019.03.007
18

I. Choi, K. Lee, An experimental study on combustion instability in model gas turbine combustor using simulated SNG fuel, J. Korean Soc. Combust. 20 (2015) 32-42.

10.15231/jksc.2015.20.1.032
19

A. Kourmatzis, P.X. Pham, A.R. Masri, Characterization of atomization and combustion in moderately dense turbulent spray flames, Combust. Flame 162 (2015) 978-996.

10.1016/j.combustflame.2014.09.021
20

T. Xiao, V. Gupta, A.R.W. Macfarlane, C. Kennedy, M.J. Dunn, A. Kourmatzis, J.L. Torero, A.R. Masri, On the structure of buoyant fires with varying levels of fuel-turbulence, Combust. Flame 257 (2023) 112993.

10.1016/j.combustflame.2023.112993
21

M. Raffel, C.E. Willert, F. Scarano, C.J. Kähler, S.T. Wereley, J. Kompenhans, Particle Image Velocimetry: A Practical Guide, 3rd ed., Springer, Cham, 2018.

10.1007/978-3-319-68852-7
22

W. Thielicke, R. Sonntag, Particle Image Velocimetry for MATLAB: Accuracy and enhanced algorithms in PIVlab, J. Open Res. Softw. 9 (2021) 12.

10.5334/jors.334
23

A. Sciacchitano, B. Wieneke, PIV uncertainty propagation, Meas. Sci. Technol. 27 (2016) 084006.

10.1088/0957-0233/27/8/084006
Information
  • Publisher :The Korean Society of Combustion
  • Publisher(Ko) :한국연소학회
  • Journal Title :Journal of the Korean Society of Combustion
  • Journal Title(Ko) :한국연소학회지
  • Volume : 31
  • No :3
  • Pages :35-46
  • Received Date : 2026-08-07
  • Revised Date : 2026-09-01
  • Accepted Date : 2026-09-01
  • DOI :https://doi.org/10.15231/jksc.2026.31.3.035
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