湍流燃烧二阶矩模型的研究进展  

Advances in Developing Second-Order Moment Turbulent Combustion Models

作　　者：周力行[1] ZHOU Li-Xing(Department of Engineering Mechanics,Tsinghua University,Beijing 100084,China)

机构地区：[1]清华大学工程力学系,北京100084

出　　处：《工程热物理学报》2021年第5期1318-1324,共7页Journal of Engineering Thermophysics

基　　金：国家自然科学基金项目(No.51390493)。

摘　　要：湍流燃烧模型在燃烧过程数值模拟中十分重要。商业软件中仍然应用的简单模型,如EBU和预设PDF模型,常常不能很好地模拟有限反应动力学。目前通行的湍流燃烧模型,如层流小火焰模型和条件矩模型,只对一定的火焰类型和火焰结构的效果较好。PDF方程模型更通用,但计算量太大,用于大涡模拟更是如此。另一类是统计矩模型,即基于湍流模型的思路,用雷诺展开和取平均,封闭未知项的二阶矩模型,但是遇到了高度非线性的温度指数函数的困难。不同研究者采取了不同的近似处理,都低估了时平均反应率。作者彻底放弃各种近似方法,构建了终版的二阶矩模型,用于不同的单相和两相燃烧的雷诺平均模拟和大涡模拟,得到了实验验证和直接数值模拟的验证。Turbulent combustion models are substantially important in simulation of combustion processes.Some simple models,still used in commercial software,like EBU and presumed-PDF models,frequently cannot well simulate the finite-rate chemistry.Present widely recognized models,as laminar flame-let and conditional moment closure models,are good only for certain flame types and flame structures.More general is the PDF equation model,but its computation requirement is very large,in particular when using in large-eddy simulation(LES).Alternatively,the statistical moment models,like second-order moment(SOM)models were developed based on the idea of turbulence modeling,i.e.the Reynolds expansion and averaging and closing the unknown terms.However the difficulty in treating the highly nonlinear exponential function of temperature in the reaction term was encountered.Different investigators adopted various approximations by neglecting different correlation terms,leading to under-predicting the time-averaged reaction rate.The present author entirely abandoned different approximations,proposed a final version of the SOM model.This final version was used in both RANS modeling and LES of different single-phase and two-phase flames.It was validated by both experimental results and direct numerical simulation(DNS).

关 键 词：湍流燃烧 CFD数值模拟 二阶矩模型 

分 类 号：TK123[动力工程及工程热物理—工程热物理]