Experimental and LES Study of H2/CH4 Premixed Gas Deflagration Under Different Obstacle Conditions

To study the influence of obstacles on the premixed gas explosion process and provide a theoretical basis for the safe use of fuel and the space configuration within weakly constrained structures, experimental and numerical simulation studies were conducted to investigate the explosion behavior of H2/CH4 premixed gas under different obstacle conditions. According to the angle and position of obstacles, 12 explosion working conditions were set up, and the flame kinetic behavior under the combined influence was obtained. The results show that increasing the direct contact area between the obstacle and the flame near the ignition source can effectively reduce the explosion effect. The explosion consequence is most serious when the obstacle is located in the middle position of the weakly constrained structure. When the obstacle is close to the vent, the later the flame reaches the vent, the more the explosion pressure peaks, and the explosion impact decreases as the angle of the obstacle decreases. In the numerical simulation, it was also found that when the flame passes through the obstacle near the ignition source, it takes on a special “jellyfish” shape toward the vent. In conclusion, the results of the study are useful for making reasonable assumptions about the location of the ignition source and the presence of obstacles based on the degree of damage to the weakly confined structure caused by the premixed gas explosion.