The effect of obstacle channel taper on explosion propagation of premixed methane‐air in a pipeline

Abstract In this study, a closed pipe measuring 3000 mm in length and 80 mm × 80 mm in cross‐section, with built‐in obstacles in six different configurations, was used to conduct explosion experiments. The aim was to investigate the effect of the obstacle channel's taper on the methane‐air explosion characteristics within the pipe. The results showed that changes in the obstacle's internal configuration led to an acceleration of the gas flow rate and the formation of turbulence downstream of the obstacle. An increase in the obstacle channel taper results in a higher flame propagation velocity downstream of the obstacle. For obstacles with the same taper size, the flame propagation velocity follows the trend: V large hole–small hole < V small hole–large hole . The larger the obstacle taper, the greater the difference in the area of the obstacle orifice, leading to a higher peak overpressure. For obstacles with the same taper size, the peak overpressure follows the trend: P small hole–large hole < P large hole–small hole . The research results can be applied to industrial safety design to improve the safety and reliability of facilities by optimizing obstacle design to reduce or mitigate hazards caused by explosive events.