Abstract Methane/hydrogen fuels are widely applied in the internal combustion engine and gas turbine due to enhanced laminar burning velocity and extended flammability limits. In order to ensure energy utilization in safety, the flame characteristics and explosion pressure in the lean, stoichiometric and rich mixture are investigated systematically by varying hydrogen addition and initial pressure. In the lean and stoichiometric mixture, effects of the diffusional-thermal and hydrodynamic instability on flame destabilization are enhanced with hydrogen addition. As initial pressure increase, the diffusional-thermal instability has a limited effect on flame destabilization while effects of the hydrodynamic instability continue to enhance. In the rich mixture, effects of the diffusional-thermal instability on the flame stabilization and effects of the hydrodynamic instability on the flame destabilization enhance significantly with hydrogen addition. As initial pressure increase, effects of the diffusional-thermal instability on the flame stabilization are very limited and effects of the hydrodynamic instability on the flame destabilization are enhanced. The variation in maximum explosion pressure could be neglected with hydrogen addition due to decreasing heat loss, and maximum pressure rise rate increases with hydrogen addition. Besides, explosion pressure evolution could be evaluated accurately by considering the flame instabilities. And by varying equivalence ratio, hydrogen addition and initial pressure, the most enhancing and inhibiting reactions to laminar flame velocity are H + O 2 = O + OH and H + CH 3 (+M) = CH 4 (+M), respectively.

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氢气和初始压力对甲烷/氢气燃料火焰特性和爆炸压力的影响

摘要 甲烷/氢燃料由于提高了层流燃烧速度和扩展了可燃性极限，被广泛应用于内燃机和燃气轮机中。为保证能源安全利用，通过改变加氢量和初始压力，系统研究了稀、化学计量和浓混合气的火焰特性和爆炸压力。在贫化学计量混合物中，扩散-热和流体动力学不稳定性对火焰不稳定的影响随着氢气的加入而增强。随着初始压力的增加，扩散热不稳定性对火焰不稳定的影响有限，而流体动力不稳定性的影响继续增强。在丰富的混合物中，扩散热不稳定性对火焰稳定性的影响和流体动力学不稳定性对火焰失稳的影响随着氢气的加入而显着增强。随着初始压力的增加，扩散热不稳定性对火焰稳定性的影响非常有限，流体力学不稳定性对火焰失稳的影响增强。由于热损失减少，加氢最大爆炸压力的变化可以忽略不计，而最大压力上升率随着加氢而增加。此外，可以通过考虑火焰不稳定性来准确评估爆炸压力的演变。通过改变当量比、氢气添加量和初始压力，