Numerical and Experimental Study on Flame Dynamics of the Premixed Methane-Air Mixture at Different Ignition Positions in a Two-Side 45° Branch Tube

Zhuangzhuang Xu; Haoxin Deng; Xiaoping Wen; Fahui Wang; Guoyan Chen; Mengmeng Yan; Shengnan Wei

doi:10.1021/acsomega.2c05553

Numerical and Experimental Study on Flame Dynamics of the Premixed Methane-Air Mixture at Different Ignition Positions in a Two-Side 45° Branch Tube

ACS Omega. 2023 Jan 11;8(3):2953-2964. doi: 10.1021/acsomega.2c05553. eCollection 2023 Jan 24.

Authors

Zhuangzhuang Xu¹, Haoxin Deng¹, Xiaoping Wen¹, Fahui Wang¹, Guoyan Chen¹, Mengmeng Yan¹, Shengnan Wei¹

Affiliation

¹ School of Mechanical and Power Engineering, Henan Polytechnic University, Jiaozuo454003, PR China.

Abstract

The combustion characteristics of premixed methane-air flames in a half-open tube with a two-sided 45° branch structure at different ignition positions were investigated by experiments and large eddy simulations. The numerical results were compared with the experimental results to verify the correctness of the model. The results show that the simulation results are highly consistent with the experiment. This study provides a basic understanding of the effects of the branch tube structure and the ignition position on flame dynamics. When the flame propagates to the branch interface, it forms a symmetrical vortex structure at the branch tube with the opposite rotation direction. When the ignition position is at IP0 and IP900, the maximum overpressures obtained in the experiment are 10.1 and 10.7 kPa, respectively, and 9.2 and 10.4 kPa in the simulation, respectively. At IP0, the Karlovitz number indicating the interaction intensity between the flame surface and the turbulence during flame propagation is a maximum of 9.2 and a minimum of 0.04. The premixed flame has a folded small flame, a corrugated small flame, and a thin reaction zone.