Study on coupling mechanism of acoustic vibration and propagating premixed flame by using laser irradiation method

• Project/Area Number: 18H03755
• Research Category: Grant-in-Aid for Scientific Research (A)
• Allocation Type: Single-year Grants
• Section: 一般
• Review Section: Medium-sized Section 19:Fluid engineering, thermal engineering, and related fields
• Research Institution: Hokkaido University
• Principal Investigator: 藤田 修 北海道大学, 工学研究院, 教授 (10183930)
• Co-Investigator(Kenkyū-buntansha): 橋本 望 北海道大学, 工学研究院, 准教授 (70392751)
• Project Period (FY): 2018-04-01 – 2023-03-31
• Project Status: Completed (Fiscal Year 2021)
• Budget Amount: ¥44,460,000 (Direct Cost: ¥34,200,000、Indirect Cost: ¥10,260,000); Fiscal Year 2021: ¥5,850,000 (Direct Cost: ¥4,500,000、Indirect Cost: ¥1,350,000); Fiscal Year 2020: ¥6,500,000 (Direct Cost: ¥5,000,000、Indirect Cost: ¥1,500,000); Fiscal Year 2019: ¥8,580,000 (Direct Cost: ¥6,600,000、Indirect Cost: ¥1,980,000); Fiscal Year 2018: ¥18,070,000 (Direct Cost: ¥13,900,000、Indirect Cost: ¥4,170,000)
• Keywords: 燃焼振動 / 予混合火炎 / 燃焼速度 / 音響モード / ガスタービン / アンモニア燃焼 / Parametric Instability / アンモニア / ルイス数 / Pressure coupling / Velocity coupling

Outline of Annual Research Achievements

本年度は、再生可能エネルギー由来の燃料として期待されるNH3に重点を置いた研究を進め、以下の３つの項目について成果を得た。
(1)管内伝播火炎の燃焼振動発生におよぼす代替燃料の混入割合の影響：再生可能エネルギー由来の燃料として期待されるNH3を選択し、その代替率と不安定性が発現する限界条件の関係を実験的に取得した。この結果、混合燃料（NH3とCH4の混合）中のNH3比率に対する不安定性の変化を特定の当量比について取得し、NH3の混合割合が増加すると燃焼振動の発生限界が拡大することを示した。また、この結果について考察を行い、NH3による燃料代替率が上昇するとルイス数が低下することが大きな影響を与えている可能性を指摘した。また、NH3を混入すると伝播管内で不安定性の増幅する火炎位置が変化するという結果が得られており、Pressure Couplingの不安定性への寄与を考慮する必要性を示した。
(2)平面火炎の圧力変動に対する不安定現象発現時の火炎構造の観察：従来から炭化水素燃料を対象として行ってきた、平面火炎に現れるParametric Instability発生時の詳細構造をNH3火炎を対象として観察し、炭化水素を燃料とした場合と比較を行った。この結果、火炎面に現れるセル構造の波数や発光強度の時間変化は両者で異なり、反応過程で生じる中間生成物（H2や活性化学種）を含めた拡散係数を考慮した不安定性の議論が必要であることを示した。
(3)変形を与えた火炎の不安定性の観察：これまでの研究で確立してきたレーザ照射法により、変形させた火炎の圧力変動の増幅率や不安定性の発生限界をNH3/C2H4混合燃料に対して調べた。この結果、火炎変形はNH3混合燃料の場合でも圧力増幅率を増加させ、Velocity couplingは依然として燃焼振動を発生させる重要な機構の一つであることが示された。また、純粋な炭化水素燃料と比較すると(1)でも述べたとおりNH3の混入が不安定性を増加させるという結果が得られた。

Research Progress Status

令和3年度が最終年度であるため、記入しない。

Strategy for Future Research Activity

令和3年度が最終年度であるため、記入しない。

Research Products

• [Int'l Joint Research] Indian Institute of Technology Roorkee(インド)
• [Journal Article] Acoustic parametric instability, its suppression and a beating instability in a mesoscale combustion tube (2021)
  • Author(s): Dubey Ajit Kumar、Koyama Yoichiro、Hashimoto Nozomu、Fujita Osamu
  • Journal Title: Combustion and Flame Volume: 228 Pages: 277-291
  • DOI: 10.1016/j.combustflame.2021.02.006
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Effect of flame surface area of downward propagating flames induced by single and double laser irradiation on transition to parametric instability (2021)
  • Author(s): Nguyen T.G. Tri, Ajit K. Dubey, Nozomu Hashimoto, Osamu Fujita
  • Journal Title: Combustion and Flame Volume: 223 Pages: 450-459
  • DOI: 10.1016/j.combustflame.2020.10.026
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Exploring a critical diameter for thermo-acoustic instability of downward propagating flames in tubes (2021)
  • Author(s): Ajit Kumar Dubey, Yoichiro Koyama, Nozomu Hashimoto, Osamu Fujita
  • Journal Title: Proceedings of the Combustion Institute Volume: 38 Pages: 1945-1954
  • DOI: 10.1016/j.proci.2020.06.018
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Range of “complete” instability of flat flames propagating downward in the acoustic field in combustion tube: Lewis number effect (2020)
  • Author(s): Dubey Ajit K.、Koyama Yoichiro、Yoon Sung Hwan、Hashimoto Nozomu、Fujita Osamu
  • Journal Title: Combustion and Flame Volume: 216 Pages: 326-337
  • DOI: 10.1016/j.combustflame.2020.03.003
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Experimental and theoretical study of secondary acoustic instability of downward propagating flames: Higher modes and growth rates (2019)
  • Author(s): Dubey Ajit K.、Koyama Yoichiro、Hashimoto Nozomu、Fujita Osamu
  • Journal Title: Combustion and Flame Volume: 205 Pages: 316-326
  • DOI: 10.1016/j.combustflame.2019.04.010
  • NAID: 120007098302
  • Peer Reviewed
• [Journal Article] Blowout of non-premixed turbulent jet flames with coflow under microgravity condition (2019)
  • Author(s): Wang Qiang、Hu Longhua、Wang Shaoming、Wang Shuangfeng、Chung Suk Ho、Fujita Osamu
  • Journal Title: Combustion and Flame Volume: 210 Pages: 315-323
  • DOI: 10.1016/j.combustflame.2019.08.041
  • NAID: 120007173930
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Effect of Le on criteria of transition to secondary acoustic instability of downward-propagating flame in a tube with controlled curvature induced by external laser (2019)
  • Author(s): Chung Yongho, Osamu Fujita. Nozomu Hashimoto
  • Journal Title: Proceedings of the Combustion Institute Volume: 37 Pages: 1887-1894
  • DOI: 10.1016/j.proci.2018.06.159
  • Peer Reviewed
• [Journal Article] Effect of geometrical parameters on thermo-acoustic instability of downward propagating flames in tubes (2019)
  • Author(s): Ajit KumarDubey, KoyamaYoichiro, HashimotoNozomu, FujitaOsamu
  • Journal Title: Proceedings of the Combustion Institute Volume: 37 Pages: 1869-1877
  • DOI: 10.1016/j.proci.2018.06.155
  • Peer Reviewed
• [Presentation] Experimental Study On Partial Replacement Of Nh3 Into Fuel On Combustion Instability Of downward-Propagating Premixed Ch4/O2/N2 Flames (2021)
  • Author(s): Binti Rajii A.N., Hashimoto N., Fujita O.
  • Organizer: 13th Asia-Pacific Conference on Combustion
  • Int'l Joint Research
• [Presentation] Comparative theoretical study of thermoacoustic instability with single and twin flames in closed tubes (2020)
  • Author(s): Ajit Kumar Dubey, Youhi Morii, Hisashi Nakamura, Osamu Fujita, Kaoru Maruta
  • Organizer: 第58回燃焼シンポジウム
• [Presentation] Experimental investigation on the transition to parametric instability of downward propagating flames induced by single and double laser irradiation, (2020)
  • Author(s): Nguyen Truong Gia Tri, Nozomu Hashimoto, Osamu Fujita
  • Organizer: 第58回燃焼シンポジウム
• [Presentation] アンモニア予混合火炎の伝播管内における燃焼振動の観察 (2020)
  • Author(s): 角川 新, 橋本 望, 藤田 修
  • Organizer: 第58回燃焼シンポジウム
• [Presentation] 音響学的振動にさらされた管内下方伝播予混合火炎の二次不安定性発生時に現れるセル構造の観察 (2020)
  • Author(s): 金森 拓,橋本 望, 藤田 修
  • Organizer: 第58回燃焼シンポジウム
• [Presentation] Thermoacoustic Instability of Downward Propagating Flames in a Small Diameter Tube (2019)
  • Author(s): Ajit Kumar Dubey, Yoichiro Koyama, Nozomu Hashimoto, Osamu Fujita
  • Organizer: The Second Pacific Rim Thermal Engineering Conference (PRTEC-2019)
  • Int'l Joint Research
• [Presentation] Experimental Study on Secondary Acoustic Instability in Downward-Propagating Flames in a Tube (2019)
  • Author(s): Juwon Park, Sung Hwan Yoon, Heejae Kim, Jae-Hyuk Choi, Kang-Woo Chun, Osamu Fujita,
  • Organizer: 12th Asia-Pacific Conference on Combustion (ASPACC2019)
  • Int'l Joint Research
• [Presentation] Effect of Le on Transition to Parametric Instability in Downward Propagating Flames (2019)
  • Author(s): Ajit Kumar Dubey, Yoichiro Koyama, Sung Hwan Yoon, Nozomu Hashimoto, Osamu Fujita
  • Organizer: 12th Asia-Pacific Conference on Combustion (ASPACC2019)
  • Int'l Joint Research
• [Presentation] Experimental Comparison on Transition Criteria to Parametric Instability of a Downward-propagating Flame in a Tube Induced by Single Laser Irradiation and Double Laser Irradiation (2019)
  • Author(s): Nguyen Truong Gia Tri, Nozomu Hashimoto, Osamu Fujita
  • Organizer: 12th Asia-Pacific Conference on Combustion (ASPACC2019)
  • Int'l Joint Research
• [Presentation] Effect of Boundary Conditions on Thermo-Acoustic Instability of Flames Propagating in Tubes (2019)
  • Author(s): Ajit Dubey,Osamu Fujita,Yoichiro Koyama,Nozomu Hashimoto
  • Organizer: 27th International Colloquium on the Dynamics of Explosions and Reactive Systems (27th ICDERS)
  • Int'l Joint Research
• [Presentation] Critical diameter for thermo-acoustic stability of downward propagating flames in tubes (2019)
  • Author(s): Ajit Dubey,Yoichiro Koyama,Nozomu Hashimoto,Osamu Fujita
  • Organizer: 第57回燃焼シンポジウム
• [Presentation] Effect of Boundary Conditions on Thermo-Acoustic Instability of Flames Propagating in Tubes (2019)
  • Author(s): Ajit Dubey,Osamu Fujita,Yoichiro Koyama,Nozomu Hashimoto
  • Organizer: 27th International Colloquium on the Dynamics of Explosions and Reactive Systems
  • Int'l Joint Research
• [Presentation] Experimental observation of parametric instability of downward propagating flame in combustion tube under higher acoustic vibration mode (2018)
  • Author(s): Yoichiro Koyama, Ajit Kumar Dubey, Nozomu Hashimoto, Osamu Fujita
  • Organizer: 37th International Symposium on Combustion, Work-in-progress
  • Int'l Joint Research
• [Presentation] Effect of external acoustic wave on thermo-acoustic instability of downward propagating flame (2018)
  • Author(s): Tri Truong Gia Nguyen，Nozomu Hashimoto，Osamu Fujita
  • Organizer: 第56回燃焼シンポジウム
• [Presentation] Le effect on primary acoustic instability of downward propagating flame in a tube with external laser irradiation method (2018)
  • Author(s): Yongho Chung，Nozomu Hashimoto，Osamu Fujita
  • Organizer: 第56回燃焼シンポジウム
• [Presentation] Higher Mode Parametric instability of downward propagating flames in tubes (2018)
  • Author(s): Ajit Kumar Dubey，Yoichiro Koyama，Nozomu Hashimoto，Osamu Fujita
  • Organizer: 第56回燃焼シンポジウム
• [Presentation] 管内下方伝播火炎における高次音響モードに対する パラメトリック不安定性の実験的観察 (2018)
  • Author(s): 小山 陽一郎, Ajit Kumar Dubey, 橋本 望, 藤田 修
  • Organizer: 日本機械学会年次大会2018年度年次大会
• [Remarks] 燃焼振動と音響学的不安定性
  • URL: http://lsu-eng-hokudai.main.jp/project/acoustic-instability/
• [Remarks] Acoustic Instability
  • URL: http://lsu-eng-hokudai.main.jp/project/
• [Remarks] Acoustic Instability
  • URL: https://labs.eng.hokudai.ac.jp/labo/lsu/project/acoustic-instability/
• [Remarks] Acoustic Instability
  • URL: http://labs.eng.hokudai.ac.jp/labo/lsu/project/acoustic-instability/