Effects of position layout and length gradient of two side ducts of on methane/air explosion in a tube

In order to examine how two side ducts affect the dynamic behavior of a gas explosion in a tube, two side ducts were added to a tube containing a mixture of 9.5% methane and air. An experiment was conducted to release the explosion pressure and study how the position and length gradient of the side ducts influence the explosion's overpressure and the speed at which the flame spreads. Based on the data, it was found that the most effective pressure release occurred at a length of 0.2 m for the front side duct and 0.1 m for the end side duct. Additionally, the greatest explosive overpressure recorded was 2.54 kPa. A double driving effect was created between the two side ducts when they were put in the front and middle and the middle and end locations. This increased the flame propagated speed. The greatest acceleration effect on the flame front occurred at 0.2 m of side duct length. When the two side ducts were placed at the front and end of the tube, the length gradient did not have any impact on flame propagation. Instead, it was predominantly the length of the front side duct that controlled flame propagation. The pressure relief effect was more pronounced when the two side ducts had a downward gradient; however, it was affected by the length of the end side duct. A relationship equation was established between the lengths of the two side ducts (d1 and d2), positioned at the front and end locations, and the maximum flame velocity (Vmax). The analysis results of the impact of different positioning layouts and length gradients of two side ducts on flame propagation and pressure release within the tube were instrumental in ensuring the safety of personnel, equipment, and environment during energy utilization processes.