Details of the Researcher

PHOTO

Akihiro Hayakawa
Section
Institute of Fluid Science
Job title
Associate Professor
Degree

  • Dr. Eng. (Kyushu University)

Professional Memberships 4

  • 日本航空宇宙学会

  • 自動車技術会

  • 日本機械学会

  • 日本燃焼学会

Research Interests 2

  • Combustion

  • Reactive Gas Dynamics

Research Areas 1

  • Manufacturing technology (mechanical, electrical/electronic, chemical engineering) / Thermal engineering /

Awards 20

  1. Highly Cited Researchers 2025

    2025/11　クラリベイト・アナリティクス

  2. 技術賞

    2025/11　日本燃焼学会　高効率・低 NOx 液体アンモニア噴霧燃焼用マイクロガスタービン燃焼器の開発

  3. Most impactful Articles in 2023

    2025/09　ACS Publications　Mini Review of Ammonia for Power and Propulsion: Advances and Perspectives

  4. Distinguished Paper Award

    2025/02　The Combustion Institute　Emission characteristics of confined non-premixed ammonia–oxygen–nitrogen turbulent jet flames under oxygen-enriched conditions

  5. 科学技術分野の文部科学大臣表彰 若手科学者賞

    2024/04　文部科学省　カーボンニュートラルに向けた燃料アンモニアの燃焼科学研究

  6. 論文賞

    2023/11　日本燃焼学会　Measurement and modelling of the laminar burning velocity of methane-ammonia-air flames at high pressures using a reduced reaction mechanism

  7. Young Investigator Award

    2023/05　The 13th Asia-Pacific Conference on Combustion

  8. 奨励賞

    2022/11　日本燃焼学会　燃料利用に向けたアンモニアの基礎燃焼特性解明に関する研究

  9. 2022 Energy and Fuels Rising Star

    2022/10　ACS Publications

  10. 論文賞

    2020/12　日本燃焼学会　Development of a wide range-operable, rich-lean low-NOx combustor for NH3 fuel gas-turbine power generation

  11. Best Presentation Award for Young Researcher

    2019/12　16th International Conference on Flow Dynamics　Product Gas Characteristics of Strain and Swirl Stabilized Ammonia/air Flames

  12. 論文賞

    2019/11　日本燃焼学会　Science and Technology of Ammonia Combustion

  13. 部門一般表彰（講演論文表彰）

    2018/10　日本機械学会 熱工学部門　Effects of pressure on combustion characteristics of ammonia/air premixed turbulent flames in swirling flows

  14. 奨励賞（研究）

    2018/04　日本機械学会　アンモニア燃焼の基礎特性解明とその応用の研究

  15. 優秀ポスター賞

    2017/07　東北大学若手アンサンブルプロジェクト　Laser Induced Thermal Grating Spectroscopy (LITGS)による非接触温度計測とその高度化

  16. ベストプレゼンテーション賞

    2016/11　日本燃焼学会　Quantitative Temperature Measurement of High Pressure CH4/O2/N2 Laminar Flames using Laser Induced Thermal Grating Spectroscopy (LITGS)

  17. 熱工学部門 部門一般表彰（講演論文表彰）

    2012/11　日本機械学会熱工学部門　Study of Thermo-diffusive Effects on Iso-octane/air Flames at Fixed Turbulence Karlovitz Number

  18. 三浦賞

    2010/03　日本機械学会

  19. 若手優秀講演フェロー賞

    2009/03　日本機械学会　イソオクタン予混合火炎の層流および乱流燃焼特性に及ぼす二酸化炭素希釈の影響

  20. 畠山賞

    2006/03

Show all ︎Show 5

Papers 33

  1. Pressure profiles and flame behaviors of a scramjet model combustor with two-stage fuel injection for low flight Mach numbers Peer-reviewed

    Kei Norimatsu, Noriko Katsumura, Satoshi Nishiura, Taku Kudo, Akihiro Hayakawa

    Acta Astronautica　244　357-366　2026/07

    Publisher: Elsevier BV

    DOI： 10.1016/j.actaastro.2026.02.022 　

    ISSN： 0094-5765

  2. Effects of Optical Layout and Product Gas on the Temperature Measurements Using LITGS for Oxygen Enriched CH 4 /O 2 /N 2 Premixed Flames at High Pressure Peer-reviewed

    Hiromi Kondo, Yuta Mizuno, Taku Kudo, Akihiro Hayakawa

    Combustion Science and Technology　198　(7)　1720-1741　2026

    Publisher: Informa UK Limited

    DOI： 10.1080/00102202.2025.2494153 　

    ISSN： 0010-2202

    eISSN： 1563-521X

  3. Effects of a dual-cavity flameholder on the flameholding characteristics and flame behavior for low flight Mach numbers Peer-reviewed

    Kei Norimatsu, Noriko Katsumura, Satoshi Nishiura, Taku Kudo, Akihiro Hayakawa, Hideaki Kobayashi

    Acta Astronautica　238　759-768　2026/01

    Publisher: Elsevier BV

    DOI： 10.1016/j.actaastro.2025.09.024 　

    ISSN： 0094-5765

  4. Flameholding characteristics and flame behaviors of a scramjet model combustor with two-stage fuel injection for low flight Mach numbers Peer-reviewed

    Kei NORIMATSU, Noriko KATSUMURA, Satoshi NISHIURA, Taku KUDO, Akihiro HAYAKAWA

    Journal of Thermal Science and Technology　21　(2)　25-00382　2026

    Publisher: Japan Society of Mechanical Engineers

    DOI： 10.1299/jtst.25-00382 　

    eISSN： 1880-5566

  5. Gas radiation characteristics of non-premixed ammonia–oxygen–nitrogen turbulent jet flames and comparison with methane jet flames under oxygen-enriched conditions Peer-reviewed

    Yu Xia, Daichi Matsumoto, Sophie Colson, Taku Kudo, Kai Tanji, Marina Kovaleva, Akihiro Hayakawa, Hideaki Kobayashi

    Fuel　396　135274-135274　2025/09

    Publisher: Elsevier BV

    DOI： 10.1016/j.fuel.2025.135274 　

    ISSN： 0016-2361

  6. Effects of wall heat loss on emission characteristics of liquid ammonia spray combustion using a swirling burner Peer-reviewed

    Yi-Rong Chen, Gauthier Reibel, Kohei Oku, Hirofumi Yamashita, Akihiro Hayakawa, Taku Kudo, Hisayoshi Ito, K. D. Kunkuma A. Somarathne, Hideaki Kobayashi

    Applications in Energy and Combustion Science　23　100370-100370　2025/09

    Publisher: Elsevier BV

    DOI： 10.1016/j.jaecs.2025.100370 　

    ISSN： 2666-352X

  7. 非一様な対象の計測において計測領域の大きさと姿勢がLITGS による温度定 量計測結果に及ぼす影響 Peer-reviewed

    近藤 広海, 乗松 慧生, 長谷川 翔哉, 工藤 琢, 早川 晃弘

    日本燃焼学会誌　67　165-174　2025/08

  8. Free-flight and tracking experiments of a multi-parabola laser propulsion vehicle Peer-reviewed

    Masayuki Takahashi, Yuya Hayadate, Koichi Mori, Akihiro Hayakawa

    Scientific Reports　15　(1)　2025/05/03

    Publisher: Springer Science and Business Media LLC

    DOI： 10.1038/s41598-025-00429-0 　

    eISSN： 2045-2322

    More details Close

    Abstract A free-flight experiment involving a multi-parabola laser propulsion vehicle was conducted using repetitive laser pulses at a repetition frequency of 50 Hz and an energy of 4.93 J per pulse. Observations made with a camera indicated that the vehicle achieved a maximum altitude of 110 mm; however, it deviated from the laser beam line due to initial misalignment of the laser setup. To improve flight stability, we developed a tracking system to monitor the vehicle’s motion and control the laser irradiation position. Performance requirements were assessed based on the free-flight experiment data, revealing that the vehicle attained a maximum translational speed of 0.08 m/s before deviation occurred. Our tracking system was evaluated to have a trackable speed of 0.09 m/s, meeting the performance requirements for free flight and capable of stabilizing the repetitive pulse flight of a laser propulsion vehicle.

  9. Visualization of liquid ammonia spray using 2p-SLIPI and comparison of liquid ammonia spray and gaseous ammonia combustion in a swirl combustor at atmospheric pressure Peer-reviewed

    Hirofumi Yamashita, Akihiro Hayakawa, Kohei Oku, Sophie Colson, Gauthier Reibel, Yi-rong Chen, K. D. Kunkuma A. Somarathne, Ekenechukwu C. Okafor, Taku Tsujimura, Shintaro Ito, Masahiro Uchida, Taku Kudo, Hideaki Kobayashi

    Fuel　371　131833-131833　2024/09

    Publisher: Elsevier BV

    DOI： 10.1016/j.fuel.2024.131833 　

    ISSN： 0016-2361

  10. Optimum primary equivalence ratio for rich-lean two-stage combustion of non-premixed ammonia/methane/air and ammonia/hydrogen/air flames in a swirling flow Peer-reviewed

    Hirofumi Yamashita, Akihiro Hayakawa, Ekenechukwu C. Okafor, Sophie Colson, K. D. Kunkuma A. Somarathne, Taku Tsujimura, Shintaro Ito, Masahiro Uchida, Taku Kudo, Hideaki Kobayashi

    Fuel　368　131598-131598　2024/07

    Publisher: Elsevier BV

    DOI： 10.1016/j.fuel.2024.131598 　

    ISSN： 0016-2361

  11. OH(2,0) PLIF Measurement of the Flame Base in High-pressure H2/O2 Jet Diffusion Flame up to 5.0 MPa Peer-reviewed

    Yasuhiro HIGUCHI, Yoshio NUNOME, Satoshi TAKADA, Ryoma YOSHIKAWA, Taku KUDO, Akihiro HAYAKAWA, Hideaki KOBAYASHI

    TRANSACTIONS OF THE JAPAN SOCIETY FOR AERONAUTICAL AND SPACE SCIENCES　67　(2)　52-59　2024

    Publisher: Japan Society for Aeronautical and Space Sciences

    DOI： 10.2322/tjsass.67.52 　

    ISSN： 0549-3811

    eISSN： 2189-4205

  12. Emission characteristics of confined non-premixed ammonia–oxygen–nitrogen turbulent jet flames under oxygen-enriched conditions Peer-reviewed

    Yu Xia, Yuxuan Shen, Kodai Sakai, Daichi Matsumoto, Sophie Colson, Taku Kudo, Akihiro Hayakawa, Hideaki Kobayashi

    Proceedings of the Combustion Institute　40　(1-4)　105704-105704　2024

    Publisher: Elsevier BV

    DOI： 10.1016/j.proci.2024.105704 　

    ISSN： 1540-7489

  13. Enhancement of liquid ammonia combustion by a twin fluid atomizer Peer-reviewed

    Osamu Kurata, Okafor Ekenechukwu Chijioke, Hirofumi Yamashita, Takahiro Inoue, Taku Tsujimura, Norihiko Iki, Akihiro Hayakawa, Hideaki Kobayashi

    International Journal of Gas Turbine, Propulsion and Power Systems　15　(4)　v15n4tp02-v15n4tp02　2024

    Publisher: Gas Turbine Society of Japan

    DOI： 10.38036/jgpp.15.4_v15n4tp02 　

    eISSN： 1882-5079

  14. Laminar burning velocity and Markstein length of ammonia/air flames up to the initial mixture pressure of 2.0 MPa Peer-reviewed

    Akihiro Hayakawa, Takehiro Nagaoka, Hajime Kosada, Hiroyuki Takeishi, Taku Kudo, Hisashi Nakamura

    Proceedings of the Combustion Institute　40　(1-4)　105778-105778　2024

    Publisher: Elsevier BV

    DOI： 10.1016/j.proci.2024.105778 　

    ISSN： 1540-7489

  15. Achieving high flame stability with low NO And Zero N2O and NH3 emissions during liquid ammonia spray combustion with gas turbine combustors Peer-reviewed

    Ekenechukwu C. Okafor, Osamu Kurata, Hirofumi Yamashita, Norihiko Iki, Takahiro Inoue, Hyun Jo, Masayasu Shimura, Taku Tsujimura, Akihiro Hayakawa, Hideaki Kobayashi

    Proceedings of the Combustion Institute　40　(1-4)　105340-105340　2024

    Publisher: Elsevier BV

    DOI： 10.1016/j.proci.2024.105340 　

    ISSN： 1540-7489

  16. Towards the development of liquid ammonia/air spray combustion in a gas turbine-like combustor at moderately high pressure Peer-reviewed

    Kapuruge Don Kunkuma Amila Somarathne, Hirofumi Yamashita, Sophie Colson, Kohei Oku, Keito Honda, Ekenechukwu Chijioke Okafor, Akihiro Hayakawa, Taku Kudo, Hideaki Kobayashi

    Applications in Energy and Combustion Science　16　100215-100215　2023/12

    Publisher: Elsevier BV

    DOI： 10.1016/j.jaecs.2023.100215 　

    ISSN： 2666-352X

  17. Study on the effect of injection temperature and nozzle geometry on the flashing transition of liquid ammonia spray Peer-reviewed

    Sophie Colson, Hirofumi Yamashita, Kohei Oku, Kapuruge Don Kunkuma Amila Somarathne, Taku Kudo, Akihiro Hayakawa, Hideaki Kobayashi

    Fuel　348　128612-128612　2023/09

    Publisher: Elsevier BV

    DOI： 10.1016/j.fuel.2023.128612 　

    ISSN： 0016-2361

  18. Mini Review of Ammonia for Power and Propulsion: Advances and Perspectives Peer-reviewed

    Thibault F. Guiberti, Giuseppe Pezzella, Akihiro Hayakawa, S. Mani Sarathy

    Energy and Fuels　37　(19)　14538-14555　2023/09/01

    Publisher: American Chemical Society (ACS)

    DOI： 10.1021/acs.energyfuels.3c01897 　

    ISSN： 0887-0624

    eISSN： 1520-5029

  19. Investigation of bimodal characteristics of the droplet size distribution in condensation spray Peer-reviewed

    Junnosuke Okajima, Mitsuki Kato, Akihiro Hayakawa, Yuka Iga

    Scientific Reports　13　(1)　2023/07/25

    Publisher: Springer Science and Business Media LLC

    DOI： 10.1038/s41598-023-39087-5 　

    eISSN： 2045-2322

    More details Close

    Abstract To understand the generation process of airborne droplets during exhalation, this study investigates the mechanism of bimodal characteristics of the size distribution of droplets generated in a condensed spray flow. The phase change process in the condensed spray flow was estimated based on the droplet size distribution measured by a phase Doppler particle analyzer and the temperature distribution measured by a thermistor. On the central axis, the size distribution was unimodal in the spray interior. In contrast, bimodality of the size distribution at the outer edge of the spray flow was observed. At the edge of the spray flow, a large temperature gradient was formed. This indicates that condensation actively occurred at the outer edge. For the same reason as outlined above, condensation did not progress at the spray center because of the consumption of water vapor at the outer edge by the condensation, and the droplet diameter did not change significantly. Hence, owing to the difference in the local phase change process between the center and outer edge of the spray, large and small droplets can exist simultaneously in the middle region. As a result, the size distribution of the condensation spray is bimodal.

  20. Performance Investigation of Currently Available Reaction Mechanisms in the Estimation of NO Measurements: A Comparative Study Peer-reviewed

    Ali Alnasif, Syed Mashruk, Masao Hayashi, Joanna Jójka, Hao Shi, Akihiro Hayakawa, Agustin Valera-Medina

    Energies　16　(9)　3847-3847　2023/04/29

    Publisher: MDPI AG

    DOI： 10.3390/en16093847 　

    eISSN： 1996-1073

    More details Close

    Ammonia (NH3) has been receiving the attention of researchers as an alternative promising green fuel to replace fossil sources for energy production. However, the high NOx emissions are one of the drawbacks and restrictions of using NH3 on a broad scale. The current study investigates NO production/consumption for a 70/30 (vol%) NH3/H2 mixture using kinetic reaction mechanism concepts to shed light on the essential reaction routes that promote/inhibit NO formation. Sixty-seven kinetic reaction mechanisms from the literature have been investigated and compared with recently reported measurements at a wide range of equivalence ratios (ϕ) (0.6–1.4), atmospheric pressure and temperature conditions. Both numerical simulations and experimental measurements used the same combustion reactor configuration (premixed stabilized stagnation flame). To highlight the best kinetic model for the predicting of the NO experimental measurements of NO, a symmetric mean absolute percentage error (SMAPE) has been determined as a preliminary estimation by comparing both numerical and experimental measurements. The results found that the kinetic reaction mechanism of Glarborg showed an accurate prediction with a minor error percentage of 2% at all lean and stoichiometric conditions. Meanwhile, the kinetic model of Wang accurately predicted the experimental data with 0% error at ϕ = 1.2 and underestimated the mole fraction of NO at 1.4 ϕ with an error of 10%. The sensitivity analysis and rate of production/consumption of NO mole fractions analysis have also been implemented to highlight the most important reactions that promote/inhibit NO formation. At lean and stoichiometric conditions, Glarborg kinetic model shows that the kinetic reactions of HNO + H ⇌ NO + H2, HNO + O ⇌ NO + OH, and NH + O ⇌ NO + H are the most important reaction routes with considerable effect on NO formation for 70/30 (vol%) NH3/H2 mixture. In contrast, the reactions of NH2 + NO ⇌ N2 + H2O, NH2 + NO ⇌ NNH + OH, NH + NO ⇌ N2O + H, and N + NO ⇌ N2 + O significantly consume NO to N2, NNH, and N2O. Further, Wang’s mechanism illustrated the dominant effect of each HNO + H ⇌ NO + H2, N + OH ⇌ NO + H, NH + O ⇌ NO + H in NO formation and NH + NO ⇌ N2O + H, NH2 + NO ⇌ NNH + OH, and NH2 + NO ⇌ N2 + H2O in the consumption of NO mole fractions.

  21. Effects of the Boundary Layer Bleeding on the Flow Field and the Flameholding in the Supersonic Flow Peer-reviewed

    Kei Norimatsu, Yohei Wakita, Taku Kudo, Akihiro Hayakawa, Hideaki Kobayashi

    JOURNAL OF THE JAPAN SOCIETY FOR AERONAUTICAL AND SPACE SCIENCES　71　(2)　94-103　2023

    Publisher: Japan Society for Aeronautical and Space Sciences

    DOI： 10.2322/jjsass.71.94 　

    ISSN： 1344-6460

    eISSN： 2432-3691

  22. Experimental and numerical study of product gas and N2O emission characteristics of ammonia/hydrogen/air premixed laminar flames stabilized in a stagnation flow Peer-reviewed

    Akihiro Hayakawa, Masao Hayashi, Marina Kovaleva, Gabriel J. Gotama, Ekenechukwu C. Okafor, Sophie Colson, Syed Mashruk, Agustin Valera-Medina, Taku Kudo, Hideaki Kobayashi

    Proceedings of the Combustion Institute　39　(2)　1625-1633　2023

    Publisher: Elsevier BV

    DOI： 10.1016/j.proci.2022.08.124 　

    ISSN： 1540-7489

  23. Numerical and experimental study of product gas characteristics in premixed ammonia/methane/air laminar flames stabilised in a stagnation flow Peer-reviewed

    Marina Kovaleva, Akihiro Hayakawa, Sophie Colson, Ekenechukwu C. Okafor, Taku Kudo, Agustin Valera-Medina, Hideaki Kobayashi

    Fuel Communications　10　100054-100054　2022/03

    Publisher: Elsevier BV

    DOI： 10.1016/j.jfueco.2022.100054 　

    ISSN： 2666-0520

  24. Liquid ammonia spray combustion in two-stage micro gas turbine combustors at 0.25 MPa; Relevance of combustion enhancement to flame stability and NOx control

    Ekenechukwu C. Okafor, Osamu Kurata, Hirofumi Yamashita, Takahiro Inoue, Taku Tsujimura, Norihiko Iki, Akihiro Hayakawa, Shintaro Ito, Masahiro Uchida, Hideaki Kobayashi

    APPLICATIONS IN ENERGY AND COMBUSTION SCIENCE　7　2021/09

    DOI： 10.1016/j.jaecs.2021.100038 　

    ISSN： 2666-352X

  25. Development of a wide range-operable, rich-lean low-NOx combustor for NH3 fuel gas-turbine power generation Peer-reviewed

    Osamu Kurata, Norihiko Iki, Takahiro Inoue, Takayuki Matsunuma, Taku Tsujimura, Hirohide Furutani, Masato Kawano, Keisuke Arai, Ekenechukwu Chijioke Okafor, Akihiro Hayakawa, Hideaki Kobayashi

    Proceedings of the Combustion Institute　37　4587-4595　2019/01

    DOI： 10.1016/j.proci.2018.09.012 　

  26. エタノール予混合火炎の層流および乱流燃焼速度に及ぼす圧力の影響 Peer-reviewed

    大原和剛, 月川正善, 荒木洋介, 早川晃弘, 小林正一, 永野幸秀, 北川敏明

    日本エネルギー学会誌　89　1088-1094　2010/11

  27. 乱流Karlovitz数を揃えたイソオクタン／空気／不活性ガス予混合火炎に及ぼす熱－拡散効果の影響 Peer-reviewed

    早川晃弘, 竹尾友宏, 山下晋平, 小林正一, 北川敏明

    自動車技術会論文集　41　307-312　2010

  28. イソオクタン予混合伝播火炎への混合気希釈の影響 ―二酸化炭素希釈と窒素希釈の比較― Peer-reviewed

    早川晃弘, 丸山晃助, 黒川陽平, 小林正一, 北川敏明

    自動車技術会論文集　41　61-66　2010

  29. イソオクタン層流および乱流予混合火炎に及ぼす二酸化炭素希釈の影響－化学量論混合気の場合－ Peer-reviewed

    早川晃弘, 丸山晃助, 小林正一, 北川敏明

    自動車技術会論文集　40　1209-1215　2009

  30. メタン予混合火炎における火炎核の消炎とその発生要因 Peer-reviewed

    早川晃弘, 小林正一, 北川敏明

    自動車技術会論文集　40　811-816　2009

  31. イソオクタン予混合火炎の層流および乱流燃焼速度に及ぼす圧力の影響 Peer-reviewed

    北川敏明, 丸山晃助, 中原崇志, 角邦洋, 早川晃弘

    自動車技術会論文集　40　81-86　2009

  32. Turbulent burning velocity of hydrogen–air premixed propagating flames at elevated pressures Peer-reviewed

    33　(20)　5842-5849　2008/10

    Publisher: Elsevier BV

    DOI： 10.1016/j.ijhydene.2008.06.013 　

    ISSN： 0360-3199

  33. 断熱燃焼温度を揃えた水素・メタン・プロパン予混合火炎に対する火炎伸長の影響 Peer-reviewed

    早川晃弘, 橋本淳

    津山工業高等専門学校紀要　48　29-36　2006

Show all ︎Show first 5

Misc. 5

  1. 熱工学，燃焼技術・燃料 Invited

    早川晃弘

    機械工学年鑑2025　2025/07

  2. アンモニア燃焼の解明に向けた実験研究の手法 Invited

    早川 晃弘, 中村寿, Yi-Rong Chen

    日本ガスタービン学会誌　53　48-54　2025/02

  3. アンモニア燃焼ハイブリッド航空推進システムの検討 Invited

    大林 茂, 中村寿, 早川晃弘

    ながれ　44　155-160　2025

  4. アンモニア燃料利用に向けた基礎燃焼研究 Invited

    早川晃弘

    自動車技術会中部支部 中部支部報　93　31-36　2023/09

  5. カーボンニュートラルに向けたアンモニア燃焼基礎研究 Invited

    早川晃弘

    PETROTECH　2　111-116　2023

Presentations 103

  1. Collaborative Study for Development of Ammonia-Fueled Gas Turbine International-presentation Invited

    A. Hayakawa, M. Uchida

    4th Symposium on Ammonia Energy　2025/09/30

  2. Towards development of ammonia-fueled gas turbine: combustion and liquid ammonia spray characteristics International-presentation Invited

    A. Hayakawa

    The 3rd International Workshop on Thermal Conversion for Carbon Neutrality　2025/08/10

  3. アンモニア燃焼用低NOｘRich-leanガスタービン燃焼器の研究開発

    倉田修, 壹岐典彦, 井上貴博, 辻村拓, 古谷博秀, 河野雅人, 新井啓介, E.C. Okafor, 早川晃弘, 小林秀昭

    第56回燃焼シンポジウム　2018/11/16

  4. Efficient Low NOx Combustion Strategies for Ammonia-methane Fuel a Micro Gas Turbine Combustor

    E.C. Okafor, A. Hayakawa, R. Rattanasupapornsak, A. Hayakawa, T. Kudo, O. Kurata, N. Iki, H. Kobayashi

    第56回燃焼シンポジウム　2018/11/14

  5. Effect of Wall Quenching of a Gas Turbine- Like Combustor on Emission Characteristics of Ammonia/air Non-Premixed Swirling Flames

    K.D.K.A. Somarathne, A. Hayakawa, H. Kobayashi

    第56回燃焼シンポジウム　2018/11/14

  6. A Study of Premixed Flames interacted with Turbulent Shear Flows

    福井陽一, 佐々木央, 工藤琢, 早川晃弘, 小林秀昭

    第56回燃焼シンポジウム　2018/11/14

  7. Effects of CO2 Concentration on Flame Propagation Characteristics of CH4/CO2/air Laminar Premixed Flames under Various Equivalence Ratios and Pressures International-presentation

    A. Hayakawa, E.C. Okafor, W. Anggono

    Proceedings of the Fifteenth International Conference on Flow Dynamics (ICFD2018)　2018/11/08

  8. Effect of Wall Heat Transfer on Emission Characteristics of Ammonia/air Swirling Flames in a Gas Turbine?like Combustor International-presentation

    K. D, K. A. Somarathne, A. Hayakawa, H. Kobayashi

    Proceedings of the Fifteenth International Conference on Flow Dynamics (ICFD2018)　2018/11/08

  9. Emission Characteristics and the Structure of Ammonia-Air Flames in a Micro Gas Turbine Swirl Combustor International-presentation

    E. C. Okafor, R. Rattanasupapornsak, K. D, K. A. Somarathne, A. Hayakawa, T. Kudo, O. Kurata, N. Iki, H. Kobayashi

    Proceedings of the Fifteenth International Conference on Flow Dynamics (ICFD2018)　2018/11/08

  10. Experimental Study of Turbulent Flame Propagation of Ammonia/Air Mixture in a Fan-Stirred Closed Vessel International-presentation

    R. Ichimura, K. Hadi, N. Hashimoto, A. Hayakawa, H. Kobayashi, O. Fujita

    Proceedings of the Fifteenth International Conference on Flow Dynamics (ICFD2018)　2018/11/08

  11. Flame Front Structure of Ammonia/air Turbulent Premixed Flames in Swirling Flows under Various Pressures International-presentation

    A. Hayakawa, M. Tsukamoto, K. D, K. A. Somarathne, T. Kudo, H. Kobayashi

    Proceedings of the Fifteenth International Conference on Flow Dynamics (ICFD2018)　2018/11/08

  12. Burnt Gas Characteristics of Swirl Stabilized Ammonia/air Turbulent Premixed Flames for Various Mixture Inlet Velocity International-presentation

    M. Tsukamoto, A. Hayakawa, K. D, K. A. Somarathne, T. Kudo, H. Kobayashi

    Proceedings of the Fifteenth International Conference on Flow Dynamics (ICFD2018)　2018/11/07

  13. Effect of Shear Flow Turbulence on Premixed Flame International-presentation

    H. Sasaki, Y. Fukui, T. Kudo, A. Hayakawa, H. Kobayashi

    Proceedings of the Fifteenth International Conference on Flow Dynamics (ICFD2018)　2018/11/07

  14. Burning Velocity and Flame Structure of Ammonia/Hydrogen/Air Turbulent Premixed Flames at Elevated Pressures International-presentation

    A. Ichikawa, T. Kudo, A. Hayakawa, T. Kudo, H. Kobayashi

    Proceedings of the Fifteenth International Conference on Flow Dynamics (ICFD2018)　2018/11/07

  15. Exhaust Gas Characteristics of Bio-fuel Combustion International-presentation

    T. Abe, K. Takahashi, T. Kudo, A. Hayakawa, H. Kobayashi

    Proceedings of the Fifteenth International Conference on Flow Dynamics (ICFD2018)　2018/11/07

  16. Development of Two-dimensional Supersonic Nozzle for a Scramjet Model Combustor International-presentation

    T. Yamaguchi, T. Hizawa, T. Kudo, A. Hayakawa, H. Kobayashi

    Proceedings of the Fifteenth International Conference on Flow Dynamics (ICFD2018)　2018/11/07

  17. Two Stage Ammonia Combustion in a Gas Turbine like Combustor for Simultaneous NO and unburnt Ammonia Reductions International-presentation

    A. Hayakawa, K.D.K.A. Somarathne, M. Tsukamoto, T. Kudo, H. Kobayashi

    NH3 Topical Conference　2018/10/31

  18. Development of Low-NOx Combustor of Micro Gas Turbine Firing Ammonia Gas International-presentation

    O. Kurata, N. Iki, T. Inoue, T. Matsunuma, T. Tsujimura, H. Furutani, M. Kawano, K. Arai, E.C. Okafor, A. Hayakawa, H. Kobayashi

    NH3 Topical Conference　2018/10/31

  19. 旋回流中に保炎されたアンモニア/空気乱流予混合火炎の火炎構造

    早川晃弘, 塚本真章, K.D.K.A. Somarathne, 工藤琢, 小林秀昭

    日本機械学会 熱工学コンファレンス2018　2018/10/20

  20. Rich-lean Low-NOx Combustor for Micro Gas Turbine Firing Ammonia Gas International-presentation

    O. Kurata, N. Iki, T. Inoue, T. Matsunuma, T. Tsujimura, H. Furutani, M. Kawano, K. Arai, E.C. Okafor, A. Hayakawa, H. Kobayashi

    Asian Congress on Gas Turbines　2018/08/24

  21. Science and technology of ammonia combustion International-presentation

    H. Kobayashi, A. Hayakawa, K.D.K.A. Somarathne, E.C. Okafor

    37th International Symposium on Combustion　2018/08/03

  22. Development of wide range operable, rich-lean low-NOx combustor for NH3 fuel gas-turbine power generations International-presentation

    O. Kurata, N. Iki, T. Inoue, T. Matsunuma, T. Tsujimura, H. Furutani, M. Kawano, K. Arai, E.C. Okafor, A. Hayakawa, H. Kobayashi

    37th International Symposium on Combustion　2018/08/03

  23. Towards the development of an efficient low-NOx ammonia combustor for a micro gas turbine International-presentation

    E.C. Okafor, K.D.K.A. Somarathne, A. Hayakawa, T. Kudo, O. Kurata, N. Iki, H. Kobayashi

    37th International Symposium on Combustion　2018/08/03

  24. Research of Ammonia Combustor for Micro Gas Turbine Power Generation and High Temperature Resistance of Materials International-presentation

    N. Iki, O. Kurata, T. Inoue, T. Matsunuma, T. Tsujimura, H. Furutani, M. Kawano, E.C. Okafor, A. Hayakawa, H. Kobayashi

    37th International Symposium on Combustion　2018/08/02

  25. Application of OH(2,0) band excited planar laser-induced fluorescence measurement to high pressure H2/O2 co-axial jet diffusion flames International-presentation

    Y. Higuchi, K. Takeuchi, Y. Nunome, K. Sasaki, S. Tomioka, T. Kudo, A. Hayakawa, H. Kobayashi

    37th International Symposium on Combustion　2018/08/02

  26. Turbulent combustion characteristics of ammonia/hydrogen/air premixed flames at high pressure International-presentation

    A. Ichikawa, A. Hayakawa, T. Kudo, H. Kobayashi

    37th International Symposium on Combustion　2018/07/31

  27. Investigation of methane-ammonia chemistry from premixed and diffusion flame structures using a counterflow configuration International-presentation

    S. Colson, Y. Hirano, T. Kudo, A. Hayakawa, H. Kobayashi, D. Escudie, C. Galizzi

    37th International Symposium on Combustion　2018/07/31

  28. Quantitative measurement of temperature in oxygen enriched CH4/O2/N2 premixed flames using Laser Induced Thermal Grating Spectroscopy (LITGS) up to 1.0MPa International-presentation

    A. Hayakawa, T. Yamagami, K. Takeuchi, Y. Higuchi, T. Kudo, S. Lowe, Y. Gao, S. Hochgreb, H. Kobayashi

    37th International Symposium on Combustion　2018/07/31

  29. The Effect of Wall Heat Loss in a Gas Turbine-like Combustor on the Emission Characteristics of Ammonia (NH3)/air Swirling Flames International-presentation

    K.D.K.A. Somarathne, E.C. Okafor, A. Hayakawa, H. Kobayashi

    37th International Symposium on Combustion　2018/07/30

  30. Development of Low NOx Combustor of Ammonia Fuel Gas Turbine Power Generations International-presentation

    O. Kurata, N. Iki, T. Inoue, T. Matsunuma, T. Tsujimura, H. Furutani, M. Kawano, K. Arai, A. Hayakawa, H. Kobayashi, E.C. Okafor

    22nd World Hydrogen Energy Conference　2018/06/18

  31. Development of Low NOx Combustor of Ammonia Fuel Gas Turbine Power Generations International-presentation

    O. Kurata, N. Iki, T. Inoue, T. Matsunuma, T. Tsujimura, H. Furutani, M. Kawano, K. Arai, A. Hayakawa, H. Kobayashi

    40th IEA Combustion Task Ledaders Meeting　2018/06/13

  32. NOx Reduction of a Swirl Combustor Firing Ammonia for a Micro Gas Turbine International-presentation

    N. Iki, O. Kurata, T. Inoue, T. Matsunuma, T. Tsujimura, H. Furutani, M. Kawano, A. Hayakawa, H. Kobayashi, E.C. Okafor

    ASME Turbo Expo 2018　2018/06/11

  33. CH4/NH3/air乱流予混合火炎の火炎構造に与える圧力およびアンモニア濃度の影響

    市川昌紀, 内藤佑次, 早川晃弘, 工藤琢, 小林秀昭

    第55回日本伝熱シンポジウム,　2018/05/30

  34. Achievement of Low NOx Emission on From Ammonia Micro Gas Turbine Combustor

    E.C. Okafor, A. Hayakawa, T. Kudo, O. Kurata, N. Iki, H. Kobayshi

    第55回日本伝熱シンポジウム,　2018/05/30

  35. Flame structure characteristics of swirl stabilized ammonia/air premixed flames International-presentation

    A. Hayakawa, M. Tsukamoto, K.D.K.A. Somarathne, T. Kudo, H. Kobayashi

    2nd European Power to Ammonia Conference　2018/05/18

  36. 水素/空気燃焼ガストーチイグナイタの噴射ガス温度推定法の検証

    山口達也, 日沢知寛, 市川太郎, 工藤琢, 早川晃弘, 小林秀昭

    日本航空宇宙学会北部支部2018年講演会ならびに第19回再使用型宇宙推進系シンポジウム　2018/03/06

  37. Laser Induced Thermal Grating Spectroscopyによる酸素富化CH4/O2/N2予混合?炎の?圧下における定量温度計測

    早川晃弘, 山上朋恭, 竹内清剛, 樋口靖浩, 工藤琢, Steven Lowe, Yi Gao, Simone Hochgreb, 小林秀昭

    日本航空宇宙学会北部支部2018年講演会ならびに第19回再使用型宇宙推進系シンポジウム　2018/03/05

  38. アンモニア燃焼ガスタービン発電装置の燃焼状態の観察

    第54回燃焼シンポジウム　2016/11/25

  39. 高圧高温火炎に対する光学計測校正バーナーの開発

    第54回燃焼シンポジウム　2016/11/25

  40. Extinction Analysis and Experiments of Methane/ammonia/air Counterflow Twin Flames

    第54回燃焼シンポジウム　2016/11/24

  41. The Effects of Pressure on Emission Reduction Characteristics of Turbulent Premixed Ammonia/air Flames Stabilized by a Swirl Burner

    第54回燃焼シンポジウム　2016/11/24

  42. Laminar Burning Velocity and Markstein Lengths of CH4-NH3-Air Premixed Flames up to Elevated Pressures

    第54回燃焼シンポジウム　2016/11/23

  43. Quantitative Temperature Measurement of High Pressure CH4/O2/N2Laminar Flames Using Laser Induced Thermal Grating Spectroscopy (LITGS)

    第54回燃焼シンポジウム　2016/11/23

  44. Gas Turbine Power Generation System firing Ammonia-Methane Mixture International-presentation

    Proceedings of the Asian Congress on Gas Turbines (ACGT2016)　2016/11/14

  45. ガスタービンにおけるアンモニア燃焼利用

    第44回日本ガスタービン学会定期講演会　2016/10/26

  46. アンモニアマイクロガスタービン燃焼器における保炎限界と燃焼排出ガス特性

    日本機械学会熱工学コンファレンス2016　2016/10/23

  47. Effect of Cavity with a Pylon on the Flame in Supersonic Flow International-presentation

    Proceedings of the Thirteenth International Conference on Flow Dynamics (ICFD2016),　2016/10/11

  48. Effects of NH3 Addition on the Laminar Burning Velocity and Markstein Length of CH4-Air Premixed Flames International-presentation

    Proceedings of the Thirteenth International Conference on Flow Dynamics (ICFD2016)　2016/10/11

  49. Flame Stabilization Limits and Emission Characteristics of an Ammonia Micro Gas Turbine Combustor International-presentation

    Proceedings of the Thirteenth International Conference on Flow Dynamics (ICFD2016),　2016/10/11

  50. Quantitative Temperature Measurement of High Pressure Flame by Using laser Induced Thermal Grating Spectroscopy (LITGS) International-presentation

    Proceedings of the Sixteenth International Symposium on Advanced Fluid Information (AFI-2016)　2016/10/11

  51. Laser Induced Thermal Grating Spectroscopy (LITGS) and Thermographic PIV for Quantitative Measurement International-presentation

    the Sixteenth International Symposium on Advanced Fluid Information (AFI-2016)　2016/10

  52. Combustion Characteristics of Ammonia/air Flames for a Model Swirl Burner and an Actual Gas Turbine Combustor International-presentation

    13th Annual 2016 NH3 Fuel Conference　2016/09/19

  53. Power generation and Flame Visualization of Micro Gas Turbine Firing Ammonia or Ammonia-Methane Mixture International-presentation

    13th Annual 2016 NH3 Fuel Conference,　2016/09/19

  54. 超音速流におけるパイロン付きキャビティー保炎器に関する研究

    第60回宇宙科学技術連合講演会　2016/09/07

  55. Numerical Investigation on Emission Reduction Characteristics of Turbulent Swirl Flames for Ammonia/air Mixture International-presentation

    36th International Symposium on Combustion　2016/08/05

  56. Flame Structure and Burning Velocity of Ammonia/Hydrogen/Air Turbulent Premixed Flames International-presentation

    36th International Symposium on Combustion　2016/08/04

  57. Extinction Characteristics of Counterflow Premixed Flames for Ammonia/air, Methane/air and Their Mixtures International-presentation

    36th International Symposium on Combustion　2016/08/02

  58. Blow-Off Limit of Ethanol Spray Flame in Swirl Flow Using a Pre-Filming Air-Blast Atomizer at Elevated Pressure International-presentation

    36th International Symposium on Combustion　2016/08/01

  59. Supersonic Combustion Using Pre-Combustion Gas Injection from a Bottom Single Hole into a Cavity Flameholder International-presentation

    36th International Symposium on Combustion　2016/08/01

  60. Micro Gas Turbine Firing Ammonia International-presentation

    roceedings of ASME Turbo Expo 2016　2016/06/17

  61. Ammonia-fired gas turbine power generation system International-presentation

    Proceedings of the 21st World Hydrogen Energy Conference 2016　2016/06/15

  62. Stabilization and Emission Characteristics of Ammonia/air Premixed Flames in Swirling Flows International-presentation

    Proceedings of the 21st World Hydrogen Energy Conference 2016　2016/06/15

  63. Numerical Investigation on the Emission Reduction Characteristics of the Turbulent Premixed Ammonia/air Flames Stabilized by a Swirl Burner

    第53回日本伝熱シンポジウム　2016/05/25

  64. Extinction Characteristics of Ammonia/Air Counterflow premixed Flames at Various Pressures International-presentation

    Proceedings of the First Pacific Rim Thermal Engineering Conference,　2016/03/16

  65. Application of OH-PLIF Measurements Using OH(2,0) Band Excitations to High Pressure H2/O2Jet Diffusion Flames International-presentation

    10th Asia-Pacific Conference on Combustion　2015/07

  66. Flame Characteristics of Ammonia/hydrogen/air Premixed Flames at Elevated Pressures International-presentation

    10th Asia-Pacific Conference on Combustion　2015/07

  67. Determination of the Entrainment and Dilution Characteristics in Confined Flames on NOx Emission

    第52回燃焼シンポジウム　2014/12

  68. Effects of Liquid Properties on Atomization Behavior and Characteristics of an Airblast Atomizer in a High Pressure Environment

    第52回燃焼シンポジウム　2014/12

  69. 高圧Ｈ2/Ｏ2噴流拡散火炎に対するＯＨ-ＰＬＩＦ計測の適用に関する研究

    第52回燃焼シンポジウム　2014/12

  70. 高圧環境における石炭改質ガス乱流予混合火炎の排出ガス特性に関する研究

    第52回燃焼シンポジウム　2014/12

  71. 高圧環境下におけるアンモニア空気予混合火炎の層流燃焼特性

    第52回燃焼シンポジウム　2014/12

  72. 超音速燃焼におけるオゾン添加による保炎性能向上に関する研究

    第52回燃焼シンポジウム　2014/12

  73. 高圧下におけるアンモニア/水素/空気予混合火炎の燃焼特性

    第25回内燃機関シンポジウム　2014/11

  74. 水素添加アンモニア/空気予混合火炎の燃焼特性に関する研究

    日本機械学会熱工学コンファレンス2014　2014/11

  75. Combustion Enhancement by Ozone Addition in Supersonic Flow International-presentation

    Eleventh International Conference on Flow Dynamics (11th ICFD 2014)　2014/10

  76. Effects of Intermediate Species on Flame Instability in Turbulent Premixed Flames of Propanol Isomers at High Pressure International-presentation

    Eleventh International Conference on Flow Dynamics (11th ICFD 2014)　2014/10

  77. Effects of Liquid Properties on Airblast Atomization in a High Pressure Environment International-presentation

    Eleventh International Conference on Flow Dynamics (11th ICFD 2014)　2014/10

  78. Experimental and Numerical Investigations of Laminar Burning Velocity of Ammonia/air Premixed Flames International-presentation

    Eleventh International Conference on Flow Dynamics (11th ICFD 2014)　2014/10

  79. Interaction between Incident Shock Wave and Pre-combustion Gas Injection from a Ramp Injector in Supersonic Flow International-presentation

    Eleventh International Conference on Flow Dynamics (11th ICFD 2014)　2014/10

  80. OH-PLIF Measurements of GH2/GO2 Diffusion Flames Using Higher Electron Excitation Bands International-presentation

    Eleventh International Conference on Flow Dynamics (11th ICFD 2014)　2014/10

  81. Effects of Ambient Pressure and Liquid Properties on Atomization Characteristics of an Airblast Atomizer International-presentation

    26th European Conference on Liquid Atomization & Spray Systems　2014/09

  82. Fundamental Characteristics of Ammonia/Air Premixed Laminar Flames International-presentation

    2014 NH3 Fuel Conference　2014/09

  83. 球状に伝播するアンモニア空気予混合火炎の層流燃焼特性

    日本機械学会2014年度年次大会　2014/09

  84. On the Role of Intermediate Species in Turbulent Premixed Combustion of Propane and Prpanol Isomers at High Pressure International-presentation

    35th International Symposium on Combustion　2014/08/08

  85. Effects of Ambient Pressure on Atomization Behavior of Airblast Atomizer International-presentation

    35th International Symposium on Combustion　2014/08/06

  86. NO Formation/Reduction Mechanisms of Ammonia/Air Premixed Laminar Flames at Various Equivalence Ratios and Ambient Pressures International-presentation

    35th International Symposium on Combustion　2014/08/06

  87. Interaction Between Pre-Combustion Gas Injection From a Ramp Injector and Incident Shockwave in Supersonic Flow International-presentation

    35th International Symposium on Combustion　2014/08/05

  88. Laminar Burning Velocity and Markstein Number of Spherically Propagating Ammonia/Air Premixed Flames International-presentation

    35th International Symposium on Combustion　2014/08/05

  89. 高圧環境におけるアンモニア空気予混合火炎からのNO生成および低減特性

    第51回日本伝熱シンポジウム　2014/05

  90. 超音速流において衝撃波干渉するキャビティー保炎器下流の火炎構造に関する研究

    日本航空宇宙学会北部支部2014年　2014/03

  91. Characteristics of Ammonia/air Laminar Premixed Flames and NO Formation/Reduction Mechanism International-presentation

    Taiwan-Japan Fuel Cell-Energy Carrier Workshop　2013/12

  92. アンモニア予混合火炎の層流燃焼速度およびNOｘ生成持性

    第51回燃焼シンポジウム　2013/12

  93. 気流噴射弁の噴霧形成過程に及ぼす雰囲気圧力の影響

    第51回燃焼シンポジウム　2013/12

  94. 高圧下におけるプロパノール異性体乱流予混合火炎の火炎構造及び不安定性に関する研究

    第51回燃焼シンポジウム　2013/12

  95. 高圧環境におけるCO/H2/CO2/O2乱流予混合火炎構造に及ぼす燃料組成の影響

    第51回燃焼シンポジウム　2013/12

  96. 高圧環境における気流噴射弁の噴霧粒径および噴霧形成過程に関する研究

    第16回微粒化アジア会議 第22回微粒化シンポジウム　2013/12

  97. 超音速流におけるランプインジェクター下流燃焼領域の衝撃波干渉に関する研究

    第51回燃焼シンポジウム　2013/12

  98. Effects of Ambient Pressure on Liquid Sheet Breakup of Airblast Atomizer International-presentation

    Tenth International Conference on Flow Dynamics　2013/11

  99. Interaction between Incident Shock Wave and Combustion Downstream of Ramp Injector in Supersonic Flow International-presentation

    Tenth International Conference on Flow Dynamics　2013/11

  100. 高圧環境におけるプロパノール異性体乱流予混合火炎の構造に関する研究

    日本機械学会熱工学コンファレンス2013　2013/10

  101. 球状伝播予混合乱流火炎の火炎面密度に及ぼす当量比の影響

    日本機械学会 2013年度年次大会大会　2013/09

  102. Experimental and Numerical Studies on Burning Velocities and Markstein Numbers on Lean Laminar H2/CH4/air Flames International-presentation

    The 9th Asia-Pacific Conference on Combustion　2013/05

  103. 球状伝播予混合乱流火炎の燃焼速度に及ぼす有効乱れ強さと火炎伸長の影響

    自動車技術会 2013年春季大会　2013/05

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Industrial Property Rights 2

  1. 低燃焼性燃料燃焼装置

    早川晃弘, 三本連太郎, 工藤琢, 小林秀昭

    Property Type: Patent

  2. スクラムジェットエンジン用燃焼装置及びスクラムジェットエンジン

    石本裕美, 小林秀昭, 工藤琢, 早川晃弘

    Property Type: Patent

Research Projects 15

  1. Clarifications of dynamics and flame-wall interaction mechanisms of liquid ammonia spray combustion at high pressure

    Offer Organization: Japan Society for the Promotion of Science

    System: Grants-in-Aid for Scientific Research

    Category: Grant-in-Aid for Scientific Research (A)

    Institution: Tohoku University

    2025/04/01 - 2029/03/31

  2. Advancement of quantitative laser measurement toward clarification of combustion science in an extreme condition

    Offer Organization: Japan Society for the Promotion of Science

    System: Grants-in-Aid for Scientific Research

    Category: Grant-in-Aid for Challenging Research (Exploratory)

    Institution: Tohoku University

    2024/06/28 - 2027/03/31

  3. Research and development of manufacturing, quality, transportation and combustion technology for fine bubble fuel for the transition period to a carbon-free society.

    Offer Organization: Japan Society for the Promotion of Science

    System: Grants-in-Aid for Scientific Research

    Category: Grant-in-Aid for Scientific Research (B)

    Institution: Kurume National College of Technology

    2023/04/01 - 2026/03/31

  4. Laminar flame structures and turbulent flame characteristics of ammonia flames at high temperature and high pressure conditions

    Offer Organization: Japan Society for the Promotion of Science

    System: Grants-in-Aid for Scientific Research

    Category: Grant-in-Aid for Scientific Research (B)

    Institution: Tohoku University

    2021/04/01 - 2024/03/31

  5. 高温高圧下における液体アンモニアおよびアンモニア水溶液の噴霧燃焼実現と現象解明

    小林 秀昭, 早川 晃弘

    Offer Organization: 日本学術振興会

    System: 科学研究費助成事業

    Category: 基盤研究(B)

    Institution: 東北大学

    2020/04/01 - 2023/03/31

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    本研究は，CO2を排出しない無機燃料である液体アンモニア(NH3)ならびに質量濃度47%までのアンモニア水溶液の高温高圧下における直接噴霧燃焼を実現し，減圧沸騰蒸発過程を有する噴霧燃焼の現象解明を行う．アンモニアは水素と並ぶCO2無排出燃料であると共に，水素に比較して保存や輸送が容易であるという優れた特徴を有している．高圧ボンベに貯蔵された液体アンモニアを加温・再加圧することなく直接噴霧燃焼させた場合の高温高圧下の乱流火炎構造と火炎安定条件，排ガス特性を実験的に明らかにし，アンモニアガスタービンへの応用に向けた基礎データを取得する．さらに，液体アンモニア噴霧燃焼をレファレンスとしてアンモニア水溶液の噴霧燃焼研究を行うことで，新しいカーボンフリー燃焼の学理構築に資する．令和３年度は，接線スワーラを内蔵した燃焼器において，昨年度成功した質量濃度30%までのアンモニア水溶液の常温空気およびメタン混焼による火炎安定化成功，レファレンスとして実施した600 Kまで予熱した空気流に対する液体アンモニア噴霧の火炎安定化成功を受けて，火炎安定化メカニズムを噴霧構造の観点からより詳細に明らかにする実験と数値解析を実施した．実験では，ホロコーンノズルによる減圧沸騰を生じる液体アンモニア噴霧と減圧沸騰を生じない水噴霧との微粒化過程の違いの可視化，ならびにダブルパルスレーザーの光干渉縞を利用して空間粒子密度の高い噴霧からの２次散乱光の影響を抑制してレーザートモグラフィーを可視化できるSLIPI法の実施，数値解析では，液体アンモニアの減圧沸騰を解析できる数理モデルを用いた非燃焼時の液体アンモニア噴霧構造の可視化，ならびに水素混焼によるアンモニア噴霧燃焼の３次元数値解析を実施した．

  6. Laser-induced fluorescence measurement of gas-liquid multiphase diffusion flames in high-pressure rocket combustion

    Kobayashi Hideaki

    Offer Organization: Japan Society for the Promotion of Science

    System: Grants-in-Aid for Scientific Research

    Category: Grant-in-Aid for Challenging Research (Exploratory)

    Institution: Tohoku University

    2020/07/30 - 2022/03/31

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    OH planer-laser-induced fluorescence measurement for gas-liquid multiphase hydrogen combustion at high pressure and high temperature applicable for rocket combustion was developed. OH(2,2) fluorescence band measurements were performed for gas H2/O2 diffusion flames at up to 5.0 MPa, and a clear flame structure with S/N ratio greater than 4 was obtained. OH(2,2) fluorescence band measurement was also applied to the gas-liquid multiphase hydrogen/liquid oxygen combustion at 3.0 MPa, and the flame structure could be observed with S/N ratio of about 2. In combustion experiments of methane/oxygen/nitrogen premixed flames up to 0.5 MPa with oxygen enrichment up to 60%, OH(2,0) band excitation and bi-directional LIF technique were combined for quantitative measurement of OH concentration, and good agreement was obtained with numerical analysis.

  7. Development of an innovative laser velocimetry without tracer particles and its application for various flow fields

    Hayakawa Akihiro

    Offer Organization: Japan Society for the Promotion of Science

    System: Grants-in-Aid for Scientific Research

    Category: Grant-in-Aid for Challenging Research (Exploratory)

    Institution: Tohoku University

    2018/06/29 - 2022/03/31

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    Development of laser diagnostics is essentially important to understand the combustion phenomena at extremely high pressure and high temperature environments, such as rocket motor. In this study, we focused on LITGS (Laser Induced Thermal Grating Spectroscopy) which is potential laser diagnostics available for high pressure environment is applied to the velocity measurement. The purpose of this study is to develop the velocity measurement method without tracer particles based on LITGS. Towards the objectives, we developed signal analysis method using FFT and the detection method of frequency modulation using heterodyne detection. The results obtained in this study are the fundamental technique for velocity measurement using LITGS with no tracer particles.

  8. Advancement and application of LITGS for quantitative temperature measurement of combustion in an extreme condition

    Hayakawa Akihiro

    Offer Organization: Japan Society for the Promotion of Science

    System: Grants-in-Aid for Scientific Research

    Category: Grant-in-Aid for Young Scientists (A)

    Institution: Tohoku University

    2017/04/01 - 2020/03/31

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    Rocket combustion is a representative combustion phenomena under an extreme condition because the orders of pressure and temperature are 10 MPa and 3000 K, respectively. Combustion measurement for such extreme condition is generally difficult using conventional laser diagnostics. In this study, it was succeeded quantitative temperature measurement of oxygen enriched methane/oxygen/nitrogen premixed flames up to 1.0 MPa using Laser Induced Thermal Grating Spectroscopy (LITGS) which is promising laser diagnostics available for high pressure combustion. In addition, it is suggested that the chromatic aberration of the crossing lens used in LITGS optics and laser intensity of the pump beam are important for the accuracy of temperature measurement using LITGS.

  9. Turbulent combustion characteristics of C3 and C4 mixed alcohol biofuel isomers in a high-pressure and high-temperature environment

    Kobayashi Hideaki

    Offer Organization: Japan Society for the Promotion of Science

    System: Grants-in-Aid for Scientific Research

    Category: Grant-in-Aid for Scientific Research (B)

    Institution: Tohoku University

    2017/04/01 - 2020/03/31

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    Combustion characteristics of C3 and C4 alcohol isomer were elucidated in a high-pressure and high-temperature environment. First, a heat release path analysis was performed and it was found that CH2O is the predominant intermediate species with high enthalpy in flame structure. By using OH-PLIF, it was proven that flame surface density for n-propanol flame is smaller than that of iso-propanol flame, indicating suppression of intrinsic flame instability in n-propanol flame. Moreover, CH2O-PLIF in terms of relationship between local flame curvature and Full-Width-Half-Maximum of CH2O profiles in a high-pressure and high-temperature environment shows that for FWHM for n-propanol flame is larger than that of iso-propanol flame in negative curvature region. The increase in FWHM of the CH2O profile suppresses the intrinsic flame instability, meaning that the theoretical prediction in terms of the effect of diffusion of intermediate species with high enthalpy was proven in this study.

  10. Spectroscopic development of laser-induced fluorescence method using higher energy band excitation for rocket combustion diagnostics

    KOBAYASHI Hideaki

    Offer Organization: Japan Society for the Promotion of Science

    System: Grants-in-Aid for Scientific Research

    Category: Grant-in-Aid for Challenging Exploratory Research

    Institution: Tohoku University

    2015/04/01 - 2017/03/31

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    In order to achieve OH-Planar Laser-Induced Fluorescence (OH-PLIF) measurements to rocket combustion which emits intense chemiluminescence, OH(2,0) band excited OH-PLIF method was developed in this study. The OH(2,1) band fluorescence was detected effectively by eliminating the interference of intense OH(0,0) band chemiluminescence, and the images of two-dimensional instantaneous OH distribution in H2/O2 jet diffusion flames were successfully acquired up to 5.9 MPa. Moreover, a calibration burner capable of adapting to high pressure and temperature flame conditions was designed to establish the quantitative optical measurement methods for rocket combustion. The oxygen-enriched CH4/O2/N2 laminar quasi one-dimensional flames were stabilized on the burner up to 0.49 MPa, with maximum flame temperature simulated to be higher than 2900 K. From these results, the primal requirements of the calibration burner were sufficiently archived.

  11. Premixed turbulent combustion characteristics taking into account the relative scales of flame and turbulence

    Hayakawa Akihiro, KOBAYASHI Hideaki

    Offer Organization: Japan Society for the Promotion of Science

    System: Grants-in-Aid for Scientific Research

    Category: Grant-in-Aid for Young Scientists (B)

    Institution: Tohoku University

    2014/04/01 - 2017/03/31

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    In order to clarify the effects of flame and turbulence scales on premixed combustion characteristics, turbulent combustion experiments were carried out using nozzle burners being outlet diameters of 14 mm, 20 mm, 40 mm and 60 mm under various mixture pressure conditions. Flame front structures were observed by OH-PLIF. The flame front wrinkling increased with an increase in burner outlet diameter. The turbulent burning velocity increased with an increase in turbulence intensity. In addition, it was clarified that the turbulent burning velocity also increased with an increase in the burner outlet diameter. Since the turbulent burning velocity of spherically propagating premixed turbulent flame increases with an increase in flame scale during flame propagation, the similar trend was also observed in the burner stabilized turbulent flame.

  12. Turbulent combustion mechanism and emission characteristics of next-generation C4-biofuel isomers in a high-pressure and high-temperature environment

    KOBAYASHI Hideaki

    Offer Organization: Japan Society for the Promotion of Science

    System: Grants-in-Aid for Scientific Research

    Category: Grant-in-Aid for Scientific Research (B)

    Institution: Tohoku University

    2014/04/01 - 2017/03/31

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    To explore the turbulent combustion mechanism of next-generation C4-biofuel isomers in a high-pressure and high-temperature environment, OH-PLIF for n-Butanol and iso-Butanol flames has been performed at pressure up to 1.0 MPa. It was found that in the regime of low turbulent intensity, maximum flame surface density of n-Butanol flame is smaller than that of iso-Butanol flame, indicating an isomer effects of biofuels at high pressure related to local structure of Butanol flames. Simultaneous measurement of NO-PLIF and OH-PLIF has been also succeeded and agreement with numerical analysis in terms of strong diffusion of NO has been confirmed. For four kinds of isomer fuels of Butanol and Butane, measurement of CO and NO emissions has been performed. CO and NO emissions from Butanol flame is weak because of oxygen containing effects, while NO emission from n-Butane flame is strongest, the mechanism being investigated based on reaction path analysis using detail chemistry.

  13. Flame structure and flame stabilization mechanism of oxygen jet diffusion flame in a high-pressure environment

    KOBAYASHI Hideaki, HAYAKAWA Akihiro

    Offer Organization: Japan Society for the Promotion of Science

    System: Grants-in-Aid for Scientific Research

    Category: Grant-in-Aid for Challenging Exploratory Research

    Institution: Tohoku University

    2012/04/01 - 2014/03/31

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    To develop safely operation method and designing mixing apparatuses for chemical plants, which mixes pure oxygen and combustible gases, characteristics of oxygen jet diffusion flames and flame stability limits in a high-pressure environment were performed. Both coaxial jet diffusion flames and transversal jet diffusion flames for pure oxygen jet in a main fuel flow were examined. Methane was used as a fuel. Results showed that, in the case of the coaxial jet flames, oxygen jet velocity is predominant for the flame stabilization and small vortexes formed at the lip of the jet tube enhance the flame stabilization. In the case of the transversal oxygen jet flames, the flow which reaches to the opposite wall plays an important role of flame stabilization, as well as flame oscillation occurs near the injection wall caused by the interaction between heat loss to the wall and high heat release in thin boundary layer at high pressure, leading to the total blow out of the flame.

  14. Turbulent combustion mechanism of isomer bio-fuels in a high-pressure, high-temperature environment

    KOBAYASHI Hideaki, HAYAKAWA Akihiro

    Offer Organization: Japan Society for the Promotion of Science

    System: Grants-in-Aid for Scientific Research

    Category: Grant-in-Aid for Scientific Research (B)

    Institution: Tohoku University

    2011/04/01 - 2014/03/31

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    For the fundamental combustion research of isomer biofuels, experiments of propanol isomers and propane turbulent premixed flame using OH-PLIF were performed in a high pressure environment. The local flame surface density for each fuel was analyzed from instantaneous turbulent flame images of cross-section. The results of the flame surface density analysis indicated differences of intrinsic flame instability for 1-propanol, 2-propanol and propane. Numerical simulations of intrinsic flame instability using a two-step reaction model as well as 1-D laminar flames using detail chemistry for propanol and propane/air mixtures were carried out to clarify the relationship between chemical reaction and flame instability. It was clarified that turbulent flame structure is highly affected by the diffusive thermal effects of C2 intermediate species, which depends on the isomer fuels and differences in dissociation reaction pathway.

  15. 圧力が予混合乱流火炎伝播特性に及ぼす影響

    早川 晃弘

    Offer Organization: 日本学術振興会

    System: 科学研究費助成事業

    Category: 特別研究員奨励費

    Institution: 九州大学

    2010 - 2012

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    本年度は,主に以下の二点について検討を行った, 一点目として,乱流火炎形状に及ぼす乱流Karlovitz数乱流Reynolds数および乱れ強さの影響について詳細に検討を行った.昨年度までの研究において,混合気初期圧力を変化させた場合,乱流Reynolds数や乱れ強さと層流燃焼速度の比なども同時に変化していた.そこで本年度は,乱流Reynolds数,乱流Karlovitz数および乱れ強さと層流燃焼速度の比を一定としたまま混合気初期圧力を変化させ,その際の乱流燃焼速度や火炎面形状について検討を行った.その結果,乱流Reynolds数を一定としたまま混合気初期圧力を高くした場合,混合気初期圧力が高くなるにつれて火炎面の大きな変形が小さくなるため,乱流火炎断面周長が短くなることが明らかとなった,また,乱れ強さと層流燃焼速度との比を一定としたまま混合気初期圧力を変化させた場合,混合気初期圧力が高くなるにつれて,火炎面に細かい凹凸が生じ,これにより乱流火炎断面周長が長くなることが明らかとなった. 二点目として,乱流燃焼モデル構築の際に重要となる,火炎面密度を実験的に求め,これらが火炎伝播や圧力によってどのように変化するかについて検討を行った,その結果,火炎面密度は火炎の半径方向に分布しており,その最大値は火炎が伝播するにつれて小さくなることを明らかとした,これは,火炎が伝播するにつれて,ブラシ厚さが増大するためであると考えられる.また,同一の火炎半径において,火炎面密度の最大値は混合気初期圧力によってあまり変化しなかった,これは,混合気初期圧力が高くなるにつれて火炎面には細かい凹凸が形成され火炎面積が増大するものの,ブラシ厚さがわずかに増大するため,火炎面密度としてはあまり変化しなかったものと考えられる.

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