Study On The Law Of Gas Fire Spreading And The Mechanisim Of Gaseous Flashover

Fire science in relation to other disciplines has a late start whether in the international or domestic. The painful lessons the fires brought were distressing and regrettable. A special stage in fire is the flashover. Flashover is a turning point in the gas phase fires and often manifested by the quick transformation a laminar flame of low burning rate into turbulent flames, which always cause strong disturbance in the field and speed up the gas mixing rate in the chamber. This made the laminar flame in a very short period time to become the turbulent combustion in the whole space range. In recent years, the frequency of gas fires is much higher, so the flame propagation law and mechanism of its development is of great significance.First, simplify and abstract the actual room, build experimental and numerical models; Secondly, research the spread of indoor flame and the law of flashover and compare the differences between different leak rate, different window opening and different amount of leakage. Through the various parameters on horizontal center line, we cloud analysis the effects of thermal buoyancy. By analyzing the velocity vector distribution we could analysis the velocity effect in the gas intake and air vent on the spread of flame, the guidance and advice in fire rescue were got in this way. The study has found the core of pressure and velocity rotation played a decisive role.By studying the spread of two-dimensional flame, the various changes of physical parameters(pressure, velocity, temperature) in the center line, we have analyzed the law of flame spread and its mechanism from the perspective of vorticity distribution both in positive and negative. By numerical simulation and experimental study, we have analyzed the dynamic process of indoor gas leak, the mechanism of flame spread, the factors that affect the surface structure of flame, the mechanism of gas phase flashover and transition conditions during flame propagation. We mainly focused on the instability of flame propagation and the effect of turbulent vortex on the flame propagation.