湍流燃烧的统一二阶矩模型

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，证实本模型更好，本模型可用于模拟详细反应动力学，其计算量远小无PDF方程模型的计算量。

A Unified Second-Order Moment Model for Turbulent Combustion

A unified second order moment model of turbulent combustion is proposed.The feature of this model is that all of the correlation terms,including the correlation of reaction rate coefficient fluctuation with the concentration flucturation,are closed by the transport equations in a unified form,accounting for the effect of chemical reaction on the dissipation of correlations.This model abandons the series expansion approximation of the exponential term or the approximation of using a product of two single variable PDF instead of a joint PDF,made in other two versions of the second order moment model.The proposed model is used to simulate methane air jet combustion and the prediction results are compared with those using the EBU Arrhenius model and other two versions of the second order moment model.Validation of predictions using the experimental data given by the Sandia National Laboratory,USA indicates that the proposed model gives better results.The model is expected to simulate the detailed chemistry,while it is much economical than the complex PDF transport equation model or the conditional moment closure model.