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提出了一种湍流燃烧统一二阶矩模型。其特点是对包括反应率系数 k的脉动和浓度脉动关联在内的所有关联量都用统一形式的二阶矩输运方程加以封闭和求解。考虑了化学反应对关联量耗散的影响 ,代替了已经提出的两种湍流燃烧二阶矩模型中 ,或用温度指数函数的级数展开近似 ,或用单变量概率密度函数乘积模拟联合概率密度函数的近似。用本模型对甲烷 -空气射流湍流扩散燃烧进行了数值模拟 ,将其结果和 EBU模型以及以前提出的两种二阶矩模型的模拟结果进行了比较 ,并用美国国家实验室的标准实验数据加以检验 ,证实本模型效果更好。本模型可用于模拟详细反应动力学 ,其计算量远小于 PDF方程模型的计算量
A unified second-order moment model of turbulent combustion is proposed. This is characterized by the fact that all associated quantities, including the pulsation and concentration pulsations with the reaction rate k, are closed and solved using the unified second-moment transport equations. Considering the influence of chemical reaction on the dissipation of correlation, instead of using the two kinds of turbulent combustion second-moment models that have been proposed, or using the exponential expansion of temperature exponential function to approximate, or using univariate probability density function to simulate the joint probability density Approximation of function The model was used to simulate the turbulent diffusion combustion of methane-air jets, and the results were compared with the EBU model and the simulation results of the two second-moment models previously proposed and verified with the standard experimental data from the National Laboratory , Confirmed that the model is better. This model can be used to simulate detailed reaction kinetics, which is far less computationally intensive than the PDF equation model