摘要
针对部分预混层流火焰,在分析了常见火焰面方程不足的基础上,使用了一套详细考虑了组分不同输运系数的火焰面方程对其进行数值模拟.模拟结果与物理空间求解结果间的比较表明,此套方程能够在保证相容性的同时获得相当好的模拟精确度.此外,在火焰面方程中采用不同的标量耗散率模型对部分预混火焰进行了数值计算,结果显示标量耗散率模型的精确程度对于模拟结果有着重要影响.进一步利用火焰面方程数值研究了部分预混层流火焰结构对于标量耗散率变化的响应,捕捉到其在低标量耗散率下区别于非预混火焰的双火焰结构的存在,并讨论了此现象产生的原因.
Partially premixed laminar flames were numerically simulated using a specific set of flamelet equations to take into account different diffusion effects.Results from the flamelet equations and those from physical space showed good consistency while consistency was also maintained within the whole equation system.Additionally,two different models of scalar dissipation rate were used in later simulations and the results indicated that a more precise model would lead to better accuracy.Furthermore,the response of the structure of partially premixed flames to the variation of scalar dissipation rates was studied using these flamelet equations.A double-flame structure which is totally different from non-premixed flame was captured at low scalar dissipation rates.Reasons for the phenomenon were also discussed.
基金
国家自然科学基金(50776085)资助
关键词
部分预混
层流火焰面方程
标量耗散率
火焰结构
partially premixed
laminar flamelet equation
scalar dissipation rate
flame structure
