Instability of flame spread in narrow channel: critical condition and dynamic behavior

2019 Fiscal Year Final Research Report

• Project/Area Number: 18K13967
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 25030:Disaster prevention engineering-related
• Research Institution: Toyohashi University of Technology
• Principal Investigator: Matsuoka Tsuneyoshi 豊橋技術科学大学, 工学(系)研究科(研究院), 准教授 (90633040)
• Project Period (FY): 2018-04-01 – 2020-03-31
• Keywords: 火災 / 燃え拡がり / 対称性 / プラスチック / 狭流路

Outline of Final Research Achievements

This is an experimental and numerical studies to investigate the mechanism which induces asymmetry of opposed flames inside a narrow channel. A new experimental system to reproduce the corresponding physical process in the gas phase of flame spread in narrow channel was developed. It is confirmed both symmetric and asymmetric flames are successfully observed with this system. In addition, flame oscillation was observed under certain conditions, though this behavior was possibly caused due to non-uniformity of the fuel velocity. Numerical simulation based on the two-dimensional model was carried out and the critical condition under which the flame becomes asymmetric was identified. Further, a potential mechanism of the asymmetric flame was proposed.

Free Research Field

燃焼工学

Academic Significance and Societal Importance of the Research Achievements

気体燃料を用いた燃焼実験により狭流路内で向かい合った火炎が非対称となる現象を再現したことは，これが可燃性固体の燃え拡がり特有の現象ではなく，同様の系で起きる一般的な現象であることを示すものとして学術的意義が大きい．火炎が非対称化する基本的物理は狭流路内の燃え拡がりにおいても同じであると考えられ，したがって本研究で得られた知見は酸素療法中の火災事故防止に役立つことが期待される．また，今後さらなる検証が必要ではあるものの，振動火炎の存在を示したことは本研究で得られた重要な知見の一つである．