低速过滤燃烧火焰面倾斜动力学因素数值预测

Numerical Predictions of Dynamical Effects on Low-Velocity Filtration Combustion Inclination Instability

采用数值手段对贫甲烷/空气预混气体低速过滤燃烧火焰面倾斜动力学因素进行数值预测。确认多孔介质内局部孔隙率分布不均匀性、初始预热段预热不均匀性等因素是火焰面倾斜不稳定性发生的动因。火焰面倾斜演变的快慢与孔隙率分布不均匀性及初始预热段预热不均匀性具有相关性,孔隙率分布及初始预热越不均匀,火焰面倾斜不稳定性发展越快。此外,将数值预测结果与实验结果分析比较,确认实验中火焰面倾斜不稳定性发生及发展是多因素叠加扰动的结果。

The dynamical effects on low-velocity filtration combustion inclination instability with lean premixed methane/air mixture are mlmerieally predicted. It is verified that the porosity non-uniformity and initial preheating non-uniformity are the dynamical factors, which can induce the emergence of flame front inclination instability. There is a positive correlation between the speed of flame front inclination evolution and the levels of porosity non-uniformity and initial preheating non-uniformity The evolution of flame front inclination instability develops faster when the porosity and initial preheating uniformity are more uneven. Moreover, by comparisons of the numerical results with the experimental data, it is demonstrated that the combination of multiple perturbation factors results in the emergence and development of flame front inclination instability in experiment.