By varying inert gas content, equivalence ratio and initial pressure, this study is aimed at investigating flame propagation behaviors and explosion pressure characteristics near suppression limit. For carbon dioxide, the weakest flame floating phenomenon is observed at Φ = 1.5 and the buoyant instability is enhanced when the equivalent ratio deviates to the rich and lean sides. For nitrogen, the buoyant instability decreases with increasing equivalent ratio. Both maximum explosion pressure and maximum pressure rise rate increase firstly and then decrease with the increase of equivalence ratio, and they decrease significantly with increasing content of carbon dioxide and nitrogen. For carbon dioxide, the critical suppression ratio of Φ = 0.6, 0.8, 1.0, 1.5 and 2.0 is 7.50, 7.18, 5.74, 3.83, and 2.87. For nitrogen, the critical suppression ratio of Φ = 0.6, 0.8, 1.0, 1.5 and 2.0 is 15.83, 11.87, 9.50, 6.33 and 4.75. Compared to nitrogen, the carbon dioxide is more effective on suppressing hydrogen explosion pressure. The adiabatic flame temperature, thermal diffusivity and mole fraction of active radicals continue to decrease with increasing content of carbon dioxide and nitrogen, which contributes to the decrease of laminar burning velocity.

通过改变惰性气体含量，当量比和初始压力，本研究旨在研究抑制极限附近的火焰传播行为和爆炸压力特性。对于二氧化碳，当Φ= 1.5时，观察到最弱的火焰漂浮现象，当当量比偏向富油和贫油时，浮力的不稳定性会增强。对于氮，浮力不稳定性随当量比的增加而降低。最高爆炸压力和最高压力上升率均随当量比的增加先增大后减小，并随着二氧化碳和氮含量的增加而显着减小。对于二氧化碳，Φ= 0.6、0.8、1.0、1.5和2.0的临界抑制比是7.50、7.18、5.74、3.83和2.87。对于氮 Φ= 0.6、0.8、1.0、1.5和2.0的临界抑制比是15.83、11.87、9.50、6.33和4.75。与氮气相比，二氧化碳在抑制氢气爆炸压力方面更有效。绝热火焰温度，热扩散率和活性自由基的摩尔分数随着二氧化碳和氮含量的增加而持续降低，这导致层流燃烧速度的降低。