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以一个带值班火焰的甲烷 空气预混射流火焰(PPJB)为研究对象,对中心射流速度分别为50 m/s (PM1-50)与200 m/s (PM1-200)的两个火焰进行RANS-PDF模拟.利用颗粒层面敏感性分析方法,研究了IEM与EMST两种混合模型在湍流预混火焰中的特性,发现对于PM1-50火焰,尽管两种混合模型对组分平均值的预测非常相似,但却对应了两种燃烧模式,EMST对应火焰传播模式,而IEM对应自着火模式;对于PM1-200火焰,两种模型均对应火焰传播模式.通过比较敏感性系数的径向分布,发现对于PM1-50火焰,增强混合或反应强度都可以促进反应进度,火焰特性同时受混合和化学反应控制.对于PM1-200火焰,在上游位置处,增强混合反而会抑制反应进度,火焰特性同时受混合和化学反应控制;在下游位置处,化学反应是火焰的控制物理过程.“,”RANS-PDF simulations have been carried out for the piloted-premixed jet burner (PPJB) flames with the central jet velocities of 50 m/s (PM1-50) and 200 m/s (PM1-200).Particle-level sensitivity analysis has been used to investigate the performance of EMST and IEM micromixing models in turbulent premixed flames.It is found that for PM1-50 flame,despite that the spatial distribution of species predicted by the two models are almost identical,the combustion modes are very different:EMST indicates a flame propagation mode,while IEM indicates an autoignition mode.For PM1-200 flame,both models indicate flame propagation processes.By comparing the radial profiles of sensitivity coefficients,it is found that for PM1-50 flame,reaction progress can be promoted by enhancing either mixing or reaction,and the flame characteristics are controlled by both mixing and reaction.In contrast,for PM1-200 flame at the upstream location,enhancing mixing may suppress combustion progress.The flame characteristic is controlled by both mixing and reaction at the upstream locations while it is solely controlled by reaction at the downstream locations.