几种二阶矩模型模拟湍流旋流燃烧的比较

本文对几种二阶矩湍流反应模型,包括统一二阶矩模型、只考虑温度脉动的二阶矩模型、只考虑浓度脉动关联的二阶矩模型、及同时考虑温度脉动和浓度脉动关联的二阶矩模型,进行了比较。将上述模型加入到FLUENT6.0软件平台上,模拟了不同旋流数下甲烷-空气的旋流燃烧。模拟结果和实验结果进行了比较,探讨了各关联量大小及其对时平均反应率的影响。结果表明,统一二阶矩湍流反应模型具有最好的模拟效果。其原因是,各种关联矩中,化学反应率系数与浓度间的脉动关联最重要。

COMPARISON OF VARIOUS SECOND-ORDER MOMENT MODELS IN MODELING TURBULENT SWIRLING COMBUSTION

Different second-order moment turbulence-chemistry models, including the unified second-order moment (USM) model, the model accounting for only the temperature fluctuation, the model accounting for only the concentration fluctuation and the model accounting for both the temperature and concentration fluctuations, are compared. These models are incorporated into the FLUENT 6.0 code and are used to simulate methane-air swirling combustion for various swirl numbers. The simulation results are compared with the corresponding measurement results, and the effect of various correlation moments is studied by comparing the magnitude of various correlations and their effect on the time-averaged reaction rate. The results show that the USM model gives the best agreement with the experimental results, because among various correlation moments the correlation of reaction-rate coefficient fluctuation with the concentration fluctuation is most important.