高Ka 数下分子扩散效应对氨气/氢气/空气预混火焰结构的影响

Simultaneous planar laser induced fluorescence (PLIF) and Rayleigh scattering thermometry (RST) were applied to measure the key species and temperature fields of premixed ammonia/ hydrogen/air jet flames to investigate the effects of differential diffusion on flame structure. NH-PLIF technique was developed to properly characterize the reaction zone of ammonia flames. Three flames with similar laminar combustion characteristics but different Lewis numbers (Le) were investigated. Results show that the reaction zone are locally thickened for all flames at high Karlovitz number (Ka). Furthermore, the reaction layer thickness increases with the Le, indicating that the differential diffusion still plays a role in the turbulent combustion even in the distributed reaction zone regime.