湍流燃烧模型在航空发动机喷雾燃烧中的应用

Application of turbulent combustion models in spray combustion of an aero-engine

使用自主开发的计算软件,数值模拟航空发动机旋流杯环形燃烧室三维湍流煤油两相燃烧过程,采用多维经验分析法与多步反应火焰面模型预测旋流杯环形燃烧室污染物排放,对4种湍流燃烧模型预测喷雾燃烧流场与污染物排放能力进行评估.各模型所得的计算值与试验数据较为相符,表明这些模型都可用来预测旋流杯环形燃烧室两相燃烧流场和污染物排放能力,但是不同模型的计算精度不相同.其中多步反应火焰面模型所得的出口温度分布与污染物排放与试验结果最接近,其预测精度高于其他模型.因此合理选择湍流燃烧模型可以提高计算准确性和可靠性.

A self-developed software was used to simulate for three-dimensional turbulent kerosene two-phase combustion processes in aero-engine annular combustor with swirl cup. Multi-dimensional empirical analysis method and multi step reaction flamelet model mechanism were used to calculate pollutant emission levels of annular eombustor with swirl cup. Prediction capability of four turbulent combustion models for spray combustion flow field and pollutant emission were analyzed and compared. Calculated results obtained by these models were in reasonable agreement with corresponding experimental data. It shows that these turbulent combustion models ean be used to predict two-phase combustion flow fields and pollutant emission of annular combustor with swirl cup. But calculation accuracy of these models are different. Outlet temperature distributions and pollutants emission obtained by the multi-step reaction flamelet model are the closest to the experimental data. Simulation accuracy of the multi-step reaction flamelet model is higher than that of other models. Then it is clear that the calculation aecuracy and reliability may be raised by adopting reasonable turbulent combustion model.