Abstract: In order to effectively widen the safety operating limits of multi-swirl staged combustor, the ignition and lean blow-out (LBO) performance of a staged model combustor were experimentally acquired. Moreover, the non-reacting flow field structures and kerosene concentration distribution in the model combustor were obtained by virtue of planar laser diagnostic techniques. The effects of the design parameters of the dual swirl prefilmed air blast pilot stage (i.e. the swirl direction and the swirl intensity) on flow field structures and kerosene concentration distribution as well as combustion stability are analyzed. Based on the analyses, the inherent correlations between the ignition / lean blow-out behaviors and the flow structures and kerosene concentration are discussed and explored. Finally, conclusions are drawn that the ignition and LBO performances of this kind of staged combustor can be improved by reducing the inner swirl intensity, increasing the outer swirl intensity and designing the pilot dual swirlers with counter-rotation. The findings and conclusions from this investigation can be used in the design of the prefilmed air blast pilot stage of the staged combustor.

Key words: Ignition;Lean blow-out;Flow structure;Kerosene concentration distribution

摘要： 为了有效拓宽多级旋流分级燃烧室的稳定工作边界，在模型燃烧室上开展了分级燃烧室点火和熄火特性试验研究，采用平面激光测量技术获得了燃烧室冷态流场结构和燃油浓度分布，分析了双级旋流预膜式空气雾化预燃级设计参数（两级旋流旋向、旋流强度）对流场结构、燃油浓度分布和燃烧稳定性的影响，并阐明了燃烧室点火和熄火特性与流场结构和燃油浓度分布的内在关联机制。结果表明，预燃级两级旋流反旋、适当减小内级旋流强度和增大外级旋流强度有利于改善这类分级燃烧室的点火和熄火特性。相关研究结论能够应用于分级燃烧室预膜式空气雾化预燃级设计。

关键词: 点火;熄火;流场结构;燃油浓度分布