预燃级旋流数对中心分级燃烧室点火性能影响

Effect of swirl number of pilot stage on ignition performance of centrally-staged combustor

为了研究预燃级旋流数对中心分级燃烧室点火性能的影响规律,对采用3种不同内外旋流强度预燃级的中心分级燃烧室进行了常温常压、常温低压的贫油点火试验,获得了贫油点火边界曲线。点火试验结果表明内弱旋流外强旋流预燃级点火性能最好,增大预燃级内旋流强度不利于点火。研究进一步采用米氏散射技术测量了3种方案预燃级出口的燃油空间分布特性,测量结果表明增大预燃级内旋流强度会使喷雾张角增大,降低预燃级外旋流强度可以减小喷雾张角,内弱旋外强旋流预燃级设计能够让油雾在燃烧室中心轴线和壁面点火嘴附近都有充足的分布,从而改善燃烧室点火性能。

In order to investigate the influence of pilot stage swirl intensity on ignition performance,ignition tests using a centrally-staged combustor equipped with three different pilot stages with different inner/outer swirl numbers were carried out at atmospheric temperature and sub-and atmospheric pressures,and the ignition boundaries were obtained.The ignition test results showed that the ignition performance of inner weak swirl and outer strong swirl pilot stage had the best ignition performance,and increasing the inner swirl intensity was not conducive to ignition.The spatial distributions of the fuel spray at the outlet of the three configurations of pilot stage were measured by using the Mie scattering technology.The measurement results showed that increasing the inner swirl intensity can increase the spray angle,and reducing the outer swirl intensity can reduce the spray angle.The pilot stage with inner weak swirl and outer strong swirl led to proper fuel distribution near the central axis of the combustor and near the ignitor,thereby improving the ignition performance.The results are useful for improving ignition performance of centrally-staged combustors.