预燃级旋流数对TeLESSⅡ燃烧室贫油熄火性能影响

北京航空航天大学发展的TeLESSⅡ低排放燃烧室采用中心分级的布局方式，其中心为经典的旋流杯结构预燃级，为燃烧室提供稳定的点火源，预燃级外圈采用预混设计的单级轴向旋流器的主燃级以降低排放。研究了预燃级一级旋流器和二级旋流器的旋流数组合对燃烧室熄火性能的影响，研究表明预燃级的设计在中心分级低排放燃烧室火焰稳定中扮演重要角色。在常温常压条件下的单头部燃烧室上测量贫油熄火油气比，并通过数值计算对比分析不同方案在熄火时的气动热力特征。研究表明：回流区总温越高燃烧室贫油熄火油气比越低，二级旋流数减少有利于火焰和流场的耦合，从而提高回流区火焰稳定，拓宽贫油熄火边界。一级旋流数增加贫油熄火油气比不是随之降低。

Effect of swirl nu mber of pilot stage on TeLESSⅡcombustor's lean blow-out performance

The next generation of technology of low emission of stirred swirl (TeLESSⅡ)low-emission combustor developed by Beihang University adopted a central staged arrangement.The center of the dome was classic swirl cup pilot structure which could provide a stable ignition source for the combustor.The main stage arranged outer of the pilot stage which adopted a pre-mixed single axial cyclone design was used to reduce emission.The influence of the combination of the swirl number of the pilot first stage and the secondary stage on the blow-out performance of the combustor was studied.The pilot stage is found playing an important role in the stabilization of flame in low-emission combustor.The gas-oil ratio was measured in the single dome com-bustor under normal temperature and pressure conditions.The aerodynamic characteristics of different cases were analyzed by numerical calculation.The results show that the higher the total temperature in the recircula-tion zone is,the lower the gas-oil ratio for lean blow-out is,and the decrease of pilot secondary stage's swirl number isfavorable to the coupling between the flame and flow field.Therefore,the flame in the recirculation zone is more stable and the lean blow-out boundary becomes broader.With the increase of the pilot first stage's swirl number,the gas-oil ratio for lean blow-out is not reduced.