## 3 Analysis of Results and Discussion
### Analysis of the Effect of Air Baffles on Explosion Shock Wave Propagation
#### 3.2.1 Time Variation of Overpressure at the Top and Middle of the Gas Chamber without Baffles  
Figure 10 shows the contour of the overpressure change in the central section of the gas cabin without a gas baffle. After ignition, a combustion wave is generated in the cabin, which compresses the unburned gas to produce a compression wave, which propagates outwards as a spherical wave at the ignition point and is the first to come into contact with the upper and lower walls of the gas cabin and is reflected and superimposed, resulting in a greater overpressure at the top than at the centre. After the reflection and superposition of multiple compression waves, a plane shock wave is formed and propagates from the ignition end to the right. As shown in Figure 10, the overpressure in the gas cabin increases with time, showing a pattern of rising, then falling, and then rising again, and there are two obvious areas of overpressure. Due to the presence of the fire door, the shock wave propagates to the right side due to the superposition of reflections from the wall surface, resulting in a reflected wave in the opposite direction, and the overpressure value rises. Figure 11 shows the time variation of the overpressure at the top and middle of the gas cabin without a baffle. As can be seen from Figure 11, when the filling length is 20 m, the overpressure at the top and middle of the gas cabin is basically the same: the overpressure changes with time showing a jagged repeated fluctuation, and there are multiple peaks at each monitoring point, and the time difference between the peaks is obvious. After ignition, the shock wave propagates to the right from the ignition end and reaches the G2-50 m monitoring point, where the overpressure rises to the first peak; after the antecedent shock wave passes, the overpressure drops, and the subsequent compression wave reaches the monitoring point, where the overpressure value rises again slightly and then drops. Due to  
Figure 9: Under normal ventilation conditions, the dangerous area of the gas cabin with (**a**) No Air Baffle and (**b**) Air Baffle, when the gas leakage continues for 10 s.  
the presence of fire doors, the gas cabin is closed at both ends, the pre-driven shock wave reaches the closed end and is reflected to form a reflected wave, which propagates to each monitoring point, and the overpressure at each monitoring point reaches the second peak; due to the superposition effect of the reflected wave and the shock wave leads to a surge of overpressure near the closed end, making the second peak overpressure near the closed end greater than the first peak, as shown in Figure 11b G2-170 m after the monitoring point, and the closer to the fire door, the more obvious the superimposed effect. According to Figure 11a,b comparison, at the beginning of the explosion, the overpressure at the top of the gas cabin was significantly greater than that at the middle, while when the shock wave was transmitted to the rightmost monitoring point at 190 m, the overpressure at the top and the middle was basically the same. 2.2 Variation of Overpressure with Time in the Top and Middle of the Gas Chamber for Different Baffle Spacing Conditions  
Figure 12 shows the change in overpressure between the surface of the baffle and the wall of the nearby gas cabin when the pre-driven shock wave and the compression wave pass through the first baffle under 70 m baffle spacing conditions. As can be seen from Figure 12, after the explosion, the pre-driven shock wave first reaches the baffle because the gas cabin is 3.8 m high, the height of the baffle is 0.5 m, the pre-driven shock wave is divided into two parts by the baffle: the part above 3.3 m is reflected by the wall of the  
Figure 11: Overpressure-time curves of each monitoring points in the top and middle of the gas cabin without gas baffle. Figure 10: Contour diagram of overpressure change diagram of gas cabin without gas baffle.