中文摘要：

火焰面方法是求解非预混燃烧最有效的手段之一,但常规火焰面方程包含组分扩散系数相等及刘易斯数恒等于1的基本假设,所生成的火焰面库不适于层流非预混燃烧流场计算。针对单步全局化学反应及原子守恒两种混合分数定义存在的不足,采用守恒传输方程对混合分数重新进行了定义。然后根据物理平面层流对撞射流火焰控制方程及新混合分数定义,详细推导得出了考虑组分扩散系数及刘易斯数影响的相容火焰面方程。最后修正了TWOPNT软件包计算相容火焰面方程时影响计算稳定性及计算效率的三点不足,并通过仿真计算证实了相容火焰面方程的合理性,比较分析了火焰面方程的标量耗散率模型对火焰面库的影响。结果表明：相容火焰面方程与物理平面控制方程在新混合分数定义下生成的火焰面库比较吻合,而常规火焰面方程在火焰峰附近的温度分布,以及与单位刘易斯数差别较大的组分分布存在较大误差;当氧化剂密度与燃气密度比值及当量耗散率较小时,考虑密度变化的标量耗散率模型几乎不会对仿真结果产生影响。

英文摘要：

The flamelet method is one of the most effective means to resolving the non-premixed combustion, but the common flamelet equations is on the hypothesis of equal component diffusion coefficient and unity Lewis number and the resulting flamelet library couldn＇ t be applicable to the laminar non-premixed combustion flow field. With regard to the defect of two mix fraction definition basing on one-step global chemical reaction and element conservation, a new definition of mixture fraction is presented using the conservation transport equation. And then the consistent flamelet equation is derived in detail and proposed based on the governing equations of laminar opposed-flow diffusion flame and the new definition of mixture fraction. At last, three drawbacks of TWOPNT software which impact the computation stability and efficiency in resolving the consistent flamelet equations are modified, the validity of the flamelet equations is approved using numerical result, and the influence of scale dissipation model to the flamelet library is compared and analyzed. The results show that the flamelet library of the consistent flamelet equa- tions and the governing equations using the new mixture fraction definition are almost uniform. However, the temperature in the vicinity of flame peak and the non-unity Lewis species distribution present obvious error using the common flamelet equations. The scale dissipation model considering variable density wouldn＇ t influence the result almost when the density ratio of oxidizer and production and the scale dissipation rate in stoichiometric mix fraction are in minor value.