二甲醚及癸烷层流火焰传播速度动力学模拟

Kinetic Simulation of Laminar Flame Speeds of Dimethyl Ether and N-decane

燃料的火焰传播速度对燃烧,尤其在火焰传播、火焰驻定等方面具有重要影响。采用文献报道的详细机理进行计算,对可再生生物燃料二甲醚以及煤油的替代燃料癸烷的层流火焰传播速度进行数值模拟研究,分析了不同当量比、温度、压力对二甲醚和癸烷的层流火焰传播速度的影响,得到了包含温度、压力、当量比影响的火焰传播速度计算的经验关系式。结果表明,两种燃料的层流火焰传播速度均在当量比空间上近似呈现出抛物型分布,并均在1.1附近达到最大值;随着温度的增加而增大,且温度越高越敏感;随着压力的增加而减小,呈现出反比的关系。与文献中的实验结果对比表明,本文得到的经验公式可以在一定温度和压力范围内较准确的预测层流火焰传播速度。

The laminar flame speeds of the fuel have an important effect on combustion,in particular with regard to flame propagation. The laminar flame speeds of the renewable biofuel dimethyl ether and alternative fuel n-decane of kerosene were numerically studied,the influence of equivalence ratio,temperature and pressure on the laminar flame speed of these two fuels were analyzed by the detailed mechanism reported in the literature. The results showed that the flame speeds of dimethyl ether and n-decane present a parabolic distribution approximately as a function of the equivalence ratio and reach the maximum when the equivalence ratio is around 1.1;the flame speeds increase as the temperature increases,and is more sensitive when the temperature is higher and it decrease with the increase of pressure,present the inverse relation. Compared with the experimental results in the literature,the empirical formula obtained in this paper can relatively accurate predict the flame propagation velocity in a certain range of temperature and pressure.