Reduction effect of explosion hazard and investigation of pressure attenuation of underwater explosion by porous complex mediums

• Project/Area Number: 16K06093
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Fluid engineering
• Research Institution: Aichi Institute of Technology
• Principal Investigator: KITAGAWA Kazutaka 愛知工業大学, 工学部, 教授 (50278230)
• Co-Investigator(Kenkyū-buntansha): 大谷 清伸 東北大学, 流体科学研究所, 特任准教授 (80536748)
• Project Period (FY): 2016-04-01 – 2019-03-31
• Project Status: Completed (Fiscal Year 2018)
• Budget Amount: ¥4,680,000 (Direct Cost: ¥3,600,000、Indirect Cost: ¥1,080,000); Fiscal Year 2018: ¥780,000 (Direct Cost: ¥600,000、Indirect Cost: ¥180,000); Fiscal Year 2017: ¥1,430,000 (Direct Cost: ¥1,100,000、Indirect Cost: ¥330,000); Fiscal Year 2016: ¥2,470,000 (Direct Cost: ¥1,900,000、Indirect Cost: ¥570,000)
• Keywords: 爆発環境減衰技術 / 水中衝撃波 / 環境問題 / 水中爆発の減衰 / 爆発環境の緩和技術 / 水流ジェット軽減 / 衝撃波 / 流体工学 / 可視化

Outline of Final Research Achievements

Interaction between underwater explosion and complex media is the research topics related to injure the strong force loading in structures for undersea operation and underwater works from explosion hazards. Attenuation and reduction performance depend on structural shape, compression strength, porosity, porous structure and acoustic impedance. The research is predicting for the pressure and impulse attenuation of underwater explosion environment. Porous compressible material will be able to disperse the pressure, inertia, momentum and impulse of shock loading, bubble pulse, and bubble jet of underwater explosion. Results show that porous semicircle wall shows good performance with attenuation of underwater explosion environment.

Academic Significance and Societal Importance of the Research Achievements

衝撃波の減衰法・緩和法の信頼性を向上のために，予測・実証・検証のサイクルで実行していくシステムが必要である．現状では，水中爆発の衝撃干渉問題と爆発環境の減衰効果の検証と実証のための計測データが不足している．本研究では，衝撃波と気泡振動の減衰特性を考慮した音響インピーダンスを持つ気泡構造の複雑媒体で，水中爆発時の衝撃圧減衰，爆発ガスの気泡膨張収縮の抑制と水流ジェットの軽減による衝撃環境の減衰法の確立を目的としている．
研究結果より，衝撃波の直接波，二次衝撃波，水流ジェットの各成分に分けて，種々の空隙媒体の利用により，水中爆発減衰の有効な手段を確立した．

Research Products

• [Journal Article] グループ紹介愛知工業大学工学部機械学科高速空気力学研究室 (2017)
  • Author(s): 北川 一敬
  • Journal Title: EXPLOSION Volume: 27 Pages: 179-181
  • NAID: 40021481546
• [Presentation] Visualization of Flow Field Around the Underwater Explosion (2018)
  • Author(s): 北川一敬，大谷清伸
  • Organizer: 18th International Symposium on Flow Visualization
  • Int'l Joint Research
• [Presentation] Attenuation and Reduction Effect of Underwater Explosion by Porous Materials (2018)
  • Author(s): 北川一敬，長廣大樹，大谷清伸，小西康郁
  • Organizer: The 15th International Conference on Flow Dynamics (ICFD2018), OS18: The Seventeenth International Symposium on Advanced Fluid Information (AFI-2018) IFS Collaborative Research Forum
  • Int'l Joint Research
• [Presentation] 可変形空隙媒体による水中爆発の軽減 (2018)
  • Author(s): 北川一敬, 長廣大樹, 大谷清伸, 阿部淳
  • Organizer: 平成29年度衝撃波シンポジウム
• [Presentation] 各種形状の可変空隙媒体による水中爆発の減衰効果 (2017)
  • Author(s): 長廣大樹，大谷清伸，北川一敬
  • Organizer: 平成28年度衝撃波シンポジウム
  • Place of Presentation: ヴェルクよこすか, 神奈川県横須賀市
  • Year and Date: 2017-03-08
• [Presentation] Collision of underwater explosion with compressible porous wall (2017)
  • Author(s): K. Kitagawa, D. Nagahiro, K. Ohtani, A. Abe
  • Organizer: 31st International Symposium on Shock Waves (ISSW31)
  • Int'l Joint Research
• [Presentation] Attenuation and Reduction Effect of Underwater Explosion by Porous Materials (2017)
  • Author(s): K. Kitagawa, D. Nagahiro, K. Ohtani, Y. Konishi, A. Abe
  • Organizer: The 14th International Conference on Flow Dynamics (ICFD2017), OS18: The Seventeenth International Symposium on Advanced Fluid Information (AFI-2017) IFS Collaborative Research Forum
  • Int'l Joint Research
• [Presentation] Experimental investigation of washing effect for textile using the underwater explosion (2017)
  • Author(s): K. Kitagawa, D. Nagahiro, K. Ohtani
  • Organizer: The 6th International Symposium on Energetic Materials and their Applications (ISEM2017)
  • Int'l Joint Research
• [Presentation] 水を満たした円管内の水中爆発現象について (2017)
  • Author(s): 長廣 大樹，北川 一敬
  • Organizer: 火薬学会2017 年度春季研究発表会
• [Presentation] Attenuation and Reduction Effect of Underwater Explosion by Porous Materials (2016)
  • Author(s): K. Kitagawa, D. Nagahiro, K.Ohtani, A. Abe
  • Organizer: Thirteenth International Conference on Flow Dynamics (ICFD2016), OS17: IFS Collaborative Research Forum (AFI-2016)
  • Place of Presentation: Sendai International Center, Japan
  • Year and Date: 2016-10-10