轮毂处理对单级压气机性能的影响

在单级轴流压气机的静子内径处进行轮毂处理 ,以模拟转子尖部的机匣处理。用小型五孔探针详细测量了最佳工作状态和近失速边界状态下转子与静子叶片排下游气流的三元流场 ,特别是其端部流场。结果发现 ,对于转子叶尖失速型的级 ,静子轮毂处理不仅可以提高级的稳定裕度 ,而且也提高了转子的稳定裕度。此外对级和转子性能的变化及转子与静子之间的相互影响作了一些初步研究 ,进一步剖析了周向槽轮毂处理的扩稳机理

EFFECT OF HUB TREATMENT ON PERFORMANCE OF AN AXIAL FLOW COMPRESSOR

The hub treatment with a circumferential groove was tested on the stator hub and compared with the casing treatment over the rotor tip for a single stage axial flow compressor.The 3D flowfield at the downflow of stator and rotor blade rows,in particular its endwall flowfield,in optimum operating and near stall states were measured by a micro-five-hole probe.It was shown that stall margin can be improved not only for the single-stage(=2 96%),but also for the rotor(=2 79%),even if the onset of stall is at the rotor tip first.The reason is that the stall affected by treatment groove to retard the appearance of stall.Some initial researches have been made for improvement of performance of the single stage and rotor,as well as the relation between the rotor and stator.It is found that the trend in variation of the most performance parameters of the rotor with hub treatment is similar to that of isolated rotor with casing treatment.According to the analysis of downflow,a new flow phenomanon is clarified:the dangenous stall locates at the blade hub and near the pressure surface.The mechanism to extend stability for a hub treatment with circumferential groove is also considered.