Flame kinetic behavior of premixed hydrogen-air explosion in an obstructed channel

ABSTRACT

This research endeavors to study the kinetic behavior of hydrogen explosion flames as they pass through confined spaces with varying obstacle passage lengths using Large Eddy Simulation (LES). The model of premixed flame was customized adopting the OpenFOAM library built upon the evolution of progress variables. By considering the turbulence-induced wrinkling and stretching effects, this study accounts for the resulting increase in flame velocity. The numerical findings managed to correctly match the experimental data. Longer obstacle passages were found to give the flame more acceleration time, resulting in a higher peak propagation velocity and pressure rise rate, according to the study. The first and second peak velocity ratios were 1.09 and 1.46 for the ducts with passage lengths of 3.0 H and 0.5 H, respectively, and the proportion of the pressure rise rate was 1.26. The analysis of vortex dynamics reveals that the vorticity distribution range and intensity are proportional to the length of the obstacle channel, where the baroclinic torque and gas expansion effects are much higher than the contribution of viscous dissipation to vorticity. The study uncovered that during obstacle-induced flame acceleration and propagation, the flame is affected by the coupling effect of Rayleigh-Taylor instability (RTI) and Kelvin-Helmholtz instability (KHI) mechanisms.

KEYWORDS:

• Hydrogen explosion
• large eddy simulation
• obstacle passage length
• vortex dynamics
• instability

Acknowledgements

The financial support is gratefully acknowledged.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was supported by the Science and Technology Innovation Foundation of Dalian, China [No.2021JJ11CG004] and the Laboratory of Transport Pollution Control and Monitoring Technology [No. Z2209-030].

Notes on contributors

Zhonghua Sheng

Zhonghua Sheng is a Ph.D. degree at Dalian Maritime University. His main research fields are gas explosion and safety engineering.

Guogang Yang

Guogang Yang is a professor at Dalian Maritime University. His main research fields are gas explosion and safety engineering.

Shian Li

Shian Li is a professor at Dalian Maritime University. His main research fields are gas explosion and safety engineering.

Qiuwan Shen

Qiuwan Shen is a professor at Dalian Maritime University. Her main research fields are gas explosion and safety engineering.

Han Sun

Han Sun is a Ph.D. degree at Dalian Maritime University. His main research fields are gas explosion and safety engineering.

Zhuangzhuang Xu

Zhuangzhuang Xu is a Ph.D. degree at Dalian Maritime University. His main research fields are gas explosion and safety engineering.