Influence of obstacles on flame propagation of multicomposition mixture gas

摘要

In this paper, we experiment with city coal gas/air mixture in enclosed duct to investigate the acceleration mechanism of orifice plate obstacles on flame and its influence on explosion overpressure. Experimental results indicate that obstacle-induced turbulence can continually accelerate flame during its propagation and enhance explosion overpressure, and that flame acceleration is due to the unburned mixture heated by leading compression wave in front of flame front and the positive feedback of obstacle-induced turbulent zone to combustion process. Based on multi-material cell program, we adopt two-step chemical reaction model to simulate explosion process of city coal gas-air mixture in the duct, and the results agree well with the experimental ones.