Dynamic couplings of hydrogen/air flame morphology and explosion pressure evolution in the spherical chamber. (25th January 2018)

• Record Type: Journal Article
• Authors: Li, Yanchao; Bi, Mingshu; Zhang, Shulin; Jiang, Haipeng; Gan, Bo; Gao, Wei
• Is Part Of: International journal of hydrogen energy. Volume 43:Number 4(2018)
• Page Start: 2503
• Page End: 2513
• Publication Date: 2018-01-25
• Subjects: Flame morphology -- Explosion pressure evolution -- Wrinkled flame -- D = 7/3; Hydrogen as fuel -- Periodicals; Hydrogène (Combustible) -- Périodiques; Hydrogen as fuel; Periodicals; 665.81
• DOI: 10.1016/j.ijhydene.2017.12.044
• Languages: English
• ISSNs: 0360-3199

Abstract

Abstract: This paper aims at exploring the dynamic couplings of flame morphology and explosion pressure evolution experimentally and theoretically. In the experiment, flame morphology and explosion pressure evolution under diffusional-thermal and hydrodynamic instability are recorded using high-speed schlieren photography and pressure transducer. In the theoretical calculation, the effects of cellular flame on the explosion pressure evolution are conducted using smooth flame, D = 2.0566, 2.1 and 7/3. The results demonstrate that the cellular flame formation of various equivalence ratios could be attributed to the fact Lewis number is less than unity on the lean side. The flame destabilization of Φ = 0.8 and 3.0 with increasing initial pressure is due to the decreasing flame thickness regardless of unchangeable thermal expansion ratio. Much smaller cells formation on the cellular flame surface as the explosion pressure rises could be attributed to the joint effect of the diffusional-thermal and hydrodynamic instability. Note that the explosion pressure evolution in spherical chamber is obviously underestimated assuming the flame surface is smooth during the hydrogen/air explosion. But the explosion overpressure is overpredicted significantly with D = 7/3. The theoretical overpressure with D = 2.1 is in satisfactory agreement with experimental results. Highlights: Effects of instability on flame morphology and pressure evolution are explored. Effects of rising explosion pressure on the flame morphology are revealed. Effects of cellular structure on pressure are compared.