CFD modeling to study the effect of particle size on dispersion in 20l explosion chamber: An overview

Mine disasters occur predominantly due to methane or coal dust explosion or a combination of both.Among the top ten worst coal mine disasters in India, nine are due to coal dust explosion. The current paper describes a general overview of the parameters causing dispersion leading to coal dust explosion,and computational fluid dynamics(CFD) simulation study to observe the effects of particle size on dispersion in Indian coal mines. Turbulent kinetic energy(TKE) and velocity vector path of dust-air mixture and dust-free air were simulated to understand their effects on coal dust dispersion. The TKE contours and velocity vector paths for dust-free air were uniform and symmetrical due to resistance-free path available. The TKE contours and velocity vector paths for dust-air mixture shows the asymmetrical distribution of contours, due to entrainment of air with dust particles. Vortices were observed in velocity vector paths which gradually diminish on increment of time sequence. These vortices are dead centres where velocity and coal dust particles concentration are both zero.

Experimental investigation on dynamic response of chamber to simulate deepwater explosive

Experimental investigation was conducted for the dynamic response of a real spherical explosive chamber that can simulate 200 m deepwater explosive loaded 10 g TNT equivalent.The vibration characteristics and dynamic strength of the chamber were analyzed by measuring the strain profiles of six characteristic points on the chamber.The research results revealed the rule of the dynamic response of the chamber on different explosive loads and static pressures.It provides references for the design and development of the chamber to simulate deepwater explosion.

Propagating Characteristic of Premixed Methane-Oxygen Deflagration in the Coal Mine Lane Including a Refuge Chamber

In order to investigate detonation propagation and distribution problems of premixed CH_4 ＋ 2O_2 mixture around a concrete structure such as a refuge chamber,detonation experiments in one small size tube were conducted. A simulation method was developed to obtain the flow field load distribution in the coal mine lane and pressure load of each part for the refuge chamber. Firstly,a physical model of a full-size explosiontest lane was established,which included the refuge chamber. With the calculations of the exact initial detonation pressure,the propagation characteristics of CH_4 ＋ 2O_2 premixed mixture detonation in the lane was simulated. Simulation results of various parts from AUTODYN are recorded,and the shock wave arrival time and the pressure peak can be observed from the detonation pressure-time curve over the changing propagation distance. So curve differences in different locations cannot be ignored. Then by detonation experiments in the small size tube,detonation pressure-time curves and velocity were obtained. Finally the simulation waveform of variation curve agreed well with the experimental results,which validated the detonation simulation method. The difference between shockwaves of the two sensors confirmed that detonation wave changed along with distance and time. These results should be taken into serious consideration for the detonation progration and distribution problem in future researches.