Development of ignition method using shock waves for lean burn gas engines

• Project/Area Number: 20H02373
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Review Section: Basic Section 24020:Marine engineering-related
• Research Institution: Kyushu University
• Principal Investigator: TSURU Dasiuke 九州大学, 総合理工学研究院, 助教 (10614620)
• Project Period (FY): 2020-04-01 – 2023-03-31
• Project Status: Completed (Fiscal Year 2022)
• Budget Amount: ¥15,600,000 (Direct Cost: ¥12,000,000、Indirect Cost: ¥3,600,000); Fiscal Year 2022: ¥2,860,000 (Direct Cost: ¥2,200,000、Indirect Cost: ¥660,000); Fiscal Year 2021: ¥5,070,000 (Direct Cost: ¥3,900,000、Indirect Cost: ¥1,170,000); Fiscal Year 2020: ¥7,670,000 (Direct Cost: ¥5,900,000、Indirect Cost: ¥1,770,000)
• Keywords: 舶用機関 / ガスエンジン / 火花点火 / 衝撃波 / 点火 / 希薄予混合 / 圧縮波 / 予混合燃焼 / 副室式ガスエンジン

Outline of Research at the Start

本研究では，舶用エンジンの効率を更に向上させるために，熱損失を低減する方法として，新たな点火方法の開発を行う．点火方法の原理は，衝撃波を利用して，希薄予混合燃焼を着火させる．まず，衝撃波の条件が予混合気の着火遅れ時間・着火位置へ及ぼす影響を明らかにする．さらに，衝撃波の伝播特性を利用して，着火位置を燃焼室の中心に移動させることを検討する．

Outline of Final Research Achievements

The behavior of shock waves generated by the spark plug was observed under the same conditions as in gas engines. As a result, it was confirmed that shock waves in the pre-chamber were generated locally with strong density changes due to the interference between shock waves and wall reflected waves. It was also confirmed that shock waves were continuously generated from gas injected at high pressure exceeding 20 MPa.

Academic Significance and Societal Importance of the Research Achievements

ガスエンジンの筒内圧相当条件で衝撃波を副室形状により，反射波より密度変化の大きい波が観測でき、それらを制御できる可能性がある．よって，エンジンの効率向上を阻む原因であるホットスポット由来のノッキング回避へとつながる可能性がある．

Research Products

• [Journal Article] Examining Combustion Characteristics of Ammonia Spray in Low-speed Marine Engines (2022)
  • Author(s): 鶴 大輔
  • Journal Title: Marine Engineering Volume: 57 Issue: 3 Pages: 276-279
  • DOI: 10.5988/jime.57.276
  • ISSN: 1346-1427, 1884-3778
  • Year and Date: 2022-05-01
  • Peer Reviewed
• [Journal Article] Knock Resistance Evaluation of Methane-Based Two-Component Gases by Combustion Visualization and Analysis using RCEM (2022)
  • Author(s): Takuya Wakasugi, Hiroshi Tashima, Daisuke Tsuru
  • Journal Title: SAE Technical Papers Volume: -
  • DOI: 10.4271/2022-01-1060
  • Peer Reviewed
• [Journal Article] Influences of the pre-chamber orifices on the combustion behavior in a constant volume chamber simulating pre-chamber type medium-speed gas engines (2022)
  • Author(s): Takuya Wakasugi, Daisuke Tsuru, Hiroshi Tashima
  • Journal Title: Combustion Engines Volume: 190 Pages: 3-13
  • DOI: 10.19206/ce-148171
  • Peer Reviewed / Open Access
• [Journal Article] Study on Combustion of Ammonia Direct Injection with Pilot Fuel (2021)
  • Author(s): Daisuke Tsuru
  • Journal Title: Marine Engineering Volume: 56 Issue: 4 Pages: 624-627
  • DOI: 10.5988/jime.56.624
  • NAID: 130008071034
  • ISSN: 1346-1427, 1884-3778
  • Year and Date: 2021-07-01
• [Journal Article] PIV measurements of entrainment process of directly injected media in internal combustion engines (2021)
  • Author(s): E. A. Elsharkawy, Takahide Aoyagi, Hiroshi Tashima, Daisuke Tsuru
  • Journal Title: 14th International Symposium on Particle Image Velocimetry Volume: 1 Issue: 1 Pages: 1-8
  • DOI: 10.18409/ispiv.v1i1.184
  • Peer Reviewed / Open Access
• [Presentation] アンモニア噴霧拡散燃焼の熱発生過程と排出物特性の数値予測 (2022)
  • Author(s): 鶴大輔
  • Organizer: マリンエンジニアリング学術講演会
• [Presentation] Study on combustion of ammonia direct injection assisted by diesel spray (2021)
  • Author(s): Daisuke Tsuru, Hiroshi Tashima
  • Organizer: the 90th conference of the japan institute of marine engineering