南京理工大学学报（自然科学版）2025，Vol.49Issue(6)：711-722,12.DOI:10.14177/j.cnki.32-1397n.2025.49.06.009
含障碍管道内氢气/空气火焰加速特性及爆燃转爆轰机理研究
Investigation on flame acceleration characteristics and deflagration-to-detonation transition mechanisms in hydrogen/air mixtures within obstructed ducts
摘要
Abstract
To investigate the influence of hydrogen concentration gradients and blockage ratio distributions on flame acceleration and deflagration-to-detonation transition(DDT)mechanisms in hydrogen/air-filled obstructed ducts,large-eddy simulation(LES)based on OpenFOAM was employed to conduct numerical simulations of DDT processes.The study shows that,under three different blockage ratio distributions,two hot spot formation mechanisms are observed in homogeneous mixtures:one caused by shock focusing due to reflected compression waves induced by obstacles,and the other occurring in the mid-section of the ducts when the flame front satisfies the reaction gradient criterion.In inhomogeneous mixtures,an additional mechanism is identified:hot spots can also form in low hydrogen concentration regions swept by the Mach stem ahead of the flame front.These hot spots ultimately lead to detonation initiation.The stable propagation speed of detonation wave in inhomogeneous mixtures can reach 2 230 m/s,which is 7.2%faster than that in homogeneous mixtures.Furthermore,obstacle arrangements with a"decreasing-then-increasing"blockage ratio sequence are found to be most conducive to flame acceleration and DDT initiation.Specifically,compared to a monotonically increasing blockage ratio layout,the flame propagation distance required to achieve a stable detonation velocity is reduced by 16.3%in homogeneous mixtures and by 16.9%in inhomogeneous mixtures.The influence of hydrogen concentration gradients and blockage ratio distributions on flame acceleration and DDT processes discovered in this paper can provide a theoretical basis for industrial explosion safety prevention and control as well as the optimization of detonation propulsion systems.关键词
火焰加速/爆燃转爆轰/非均匀混合物/障碍物布置/大涡模拟Key words
flame acceleration/deflagration-to-detonation transition/inhomogeneous mixture/obstacle arrangement/large-eddy simulation分类
数理科学引用本文复制引用
Shu Biao,Zhang Guokai,Wu Yuxin,Liu Liwang,Li Wenyu,Li Bin..含障碍管道内氢气/空气火焰加速特性及爆燃转爆轰机理研究[J].南京理工大学学报（自然科学版）,2025,49(6):711-722,12.基金项目
国家自然科学基金(52278504) （52278504）
中央高校基本科研业务费专项资金(309231B8805) （309231B8805）
江苏省前沿技术研发计划(BF2024057) （BF2024057）
