障碍物管道内低温氢-空气火焰加速特性OA

To investigate fire and explosion in liquid hydrogen leakage scenarios,the effect of initial cryo-genic temperature on the flame acceleration characteristics of premixed hydrogen-air mixtures in an obstructed channel was studied.A high-precision numerical method was used to simulate hydrogen-air premixed flame propagation at different initial temperatures(300,250,and 200 K).The chemical reaction was described by a calibrated cryogenic hydrogen-air chemical-diffusive model.The results indicate that the flame acceleration process can be divided into three stages based on flame morphology evolution.In the early stage,initial cryo-genic temperature decreases the laminar flame speed,which causes slower flame acceleration under low-temperature conditions.During the intermediate stage,the increased gas expansion ratio at lower tempera-tures increases the base flame surface area,enhancing the flow-feedback effect and promoting a rapid increase in flame speed.In the late stage,the initial low temperature induces stronger flow field disturbances,leading to the rapid formation of pressure waves or shock waves.The interaction of these waves with the flame,to-gether with flame instability,results in a highly turbulent flame morphology and even triggers local detona-tion,producing pressures approximately five times higher than those under normal temperature conditions.