本文通过包含详细化学反应机理的数值模拟研究了常温常压和高温高压下Soret扩散对成气预混火焰的影响。研究重点是揭示并解释Soret扩散对合成气/空气层流火焰速度的影响。研究结果表明,合成气/空气层流火焰速度的下降主要是由H自由基的Soret扩散导致的,而H2分子Soret扩散的影响几乎可以忽略不计。这是因为主反应区和H自由基的Soret扩散是强烈耦合的。由于H自由基Soret扩散流量的增强,Soret扩散对燃烧流量的影响会随着初始温度和压力的升高而增强。
The effects of Soret diffusion on premixed syngas/air flames at normal and elevated temperatures and pressures are investigated numerically considering detailed chemistry. The emphasis is placed on assessing and interpreting the influence of Soret diffusion on the laminar flame speed of syngas/air mixtures. The results indicate that the laminar flame speed of syngas/air is mainly reduced by Soret diffusion of H radical while the influence of H2 Soret diffusion is negligible. This is due to the fact that the main reaction zone and the Soret diffusion for H radical are strongly coupled. Because of the enhancement in the Soret diffusion flux of H radical, the influence of Soret diffusion on the laminar burning flux increases with the initial temperature and pressure.