Effects of H₂-enrichment on structures of CH₄/air turbulent swirling premixed flames affected by high intensity turbulence in a gas turbine model combsutor are investigated by conducting direct numerical simulations. Two stoichiometric mixture conditions, of which volume ratio of CH₄:H₂ = 50:50 and 80:20, are simulated by considering a reduced chemistry (25 species and 111 reactions). Results showed qualitatively different flame shapes and reaction zone characteristics between the cases. For the higher H₂-ratio case, the flame is stabilized both in the inner and outer shear layers. For the lower H₂-ratio case, the flame is stabilized only in the inner shear layer and extinction occurs in the outer shear layer. Comparison of the reaction zone characteristics with unstrained and strained laminar flames in phase space showed that H₂ mass fraction for the lower H₂-ratio case and reaction rate profiles for both cases deviate from the corresponding laminar values. Analysis of fuel species conservation equation suggests that the turbulent transports are substantially influential to determine local and global flame structures. These findings would be useful for designing practical H₂-enriched gas turbine combustor in the aspect of flame structures under high intensity turbulence.

通过进行直接数值模拟，研究了H ₂富集对燃气轮机模型燃烧器中高强度湍流影响的CH ₄ /空气湍流回旋预混火焰结构的影响。 通过考虑减少的化学反应（25种化学反应和111种反应）模拟了两个化学计量的混合条件，其中CH ₄：H _2的体积比为50:50和80:20。结果表明，两种情况之间的火焰形状和反应区特性在质量上有所不同。对于较高H ₂比的情况，火焰在内部和外部剪切层中都稳定。对于较低的H ₂-比率情况下，火焰仅在内部剪切层中稳定，而熄灭在外部剪切层中发生。比较反应区特征与相空间中未应变和应变的层流火焰，表明在较低H ₂比情况下的H ₂质量分数和两种情况下的反应速率曲线均偏离相应的层流值。燃料种类守恒方程的分析表明，湍流传输对确定局部和整体火焰结构具有重大影响。这些发现对于在高强度湍流下的火焰结构方面设计实用的富含H _2的燃气轮机燃烧室将是有用的。