基于DTF和REDIM技术构建的亚网格燃烧模型及其验证

A Sub-Grid Scale Combustion Model Based on DTF and REDIM Method and Its Validation

将反应扩散流形(REDIM)技术与动态火焰增厚(DTF)模型结合起来,构建了一种新的湍流预混燃烧模型。用该模型对PRECCINSTA燃烧器全局当量比分别为0.75和0.83的两种贫燃预混旋转火焰开展大涡模拟计算,将计算结果与原DTF模型计算结果以及实验结果进行对比研究,着重分析了速度、温度以及CO2质量分数的径向分布情况。研究表明:新模型的计算结果与实验结果吻合良好,由于新模型求解的组分输运方程数目减少,计算效率比原DTF模型约提高15%;理论上,新模型可推广应用于部分预混火焰的计算,只要采用合适的REDIM化学反应表格,如二维的REDIM表格。

The reaction-diffusion manifold(REDIM)technique is utilized in combination with the dynamically thickened-flame(DTF)model,which forms a new turbulent premixed combustion model. Then the new model was used to calculate two lean premixed swirling flames in PRECCINSTA combustor via large eddy simulation,with equivalence ratios 0.75 and 0.83,respectively. The radial profiles of velocity,temperature and CO2 mass fraction were analyzed and compared with the results from original DTF model and the experimental data.The results are in good overall agreement with the corresponding experiment. Since less species transport equations are solved in REDIM-DTF model,the computational efficiency of it is about 15% higher than the original DTF model. In theory,the new model can also be applied to simulate partially premixed flames,as long as an appropriate REDIM chemistry look-up table is used,e.g. two-dimensional REDIM table.