Experimental and numerical study on flame fusion behavior of premixed hydrogen/methane explosion with two-channel obstacles

• Published in: Fuel (Guildford) 2023-02, Vol.333, p.126530, Article 126530
• Main Authors: Wang, Shuo, Xiao, Guoqing, Mi, Hongfu, Feng, Yu, Chen, Jian
• Format: Article
• Language: English
• Subjects: Flame fusion; Gas explosion; Numerical simulation; Turbulent; Two-channel obstacles
• ISSN: 0016-2361
• DOI: 10.1016/j.fuel.2022.126530

•Two-channel obstacles can cause split-fusion effects in mixed explosion flames.•The two-channel obstacle at the location of the original maximum flame propagation speed makes the largest contribution to the split flame speed.•The expansion and dissipation of the vortices behind the obstacles drive the flame fusion.•Intense turbulence can be generated at the flame boundary during flame fusion. Methane blending with hydrogen has become an effective method to utilize clean energy, the safety of which has attracted much attention. However, there is still lack of studies on the propagation characteristics of premixed flame in split conditions. Therefore, experimental and numerical studies have been conducted to investigate the explosion flame behavior of hydrogen/methane with two-channel obstacle. The effects of the position and barrier ratio of the two-channel obstacle were analyzed based on nine distinguished explosion experiments with different setups. Experimental results show that the explosion flame will generate split and fusion, during its propagation through the two-channel obstacle. The fusion behavior of the split flame changes with the position and barrier ratio of the obstacle, i.e., either complementary or merging. As the obstacle moving further away from the ignition, the maximum speed increases and then decreases. The maximum speed can be increased by more than 5 times. Additionally, the dominance of the cumulative effect of pressure at increasing leads to the monotonicity of pressure. Finally, the flame propagation process, the mechanism of flame fusion, and the turbulence intensity distribution were predicted and visualized by computational fluid dynamics (CFD) based numerical simulations.