压气机叶栅端区造型优化与数据挖掘流动机理分析

To improve flow field near endwall region of compressor and reduce total pressure loss, fillet and non-axisymmetric endwall were combined for optimization and studying flow control mechanism on the flow field. Loss source analysis indicates that, under the design condition, both passage loss and blade surface loss of the optimized profilings decrease by more than 10%. However, near-stall condition shows a significant reduction in losses across four regions except for leading edge region. And the passage dissipation intensity decreases most significantly, with passage loss reduced by over 30%.Under design condition, the endwall profiling in the optimal sample increases the overall total pressure loss by 0.024%. The fillet in the optimal sample reduces loss by 1.76%. However, the coupling scheme results in a decrease in total pressure loss by 1.88%. This indicates that the coupling scheme has a complex impact on the corner separation, and the improvement effect on loss is not simply a linear superposition of the improvements from the two individual flow control methods. Additionally, the effect of single flow control such as fillet and endwall profiling on the vortex structure is limited to the passage between blades, however fillet and endwall profiling coupled flow control not only influences the passage vortex but also makes trailing flow more uniform and significantly reduces the strength of the mixing vortex at the downstream of trailing edge. This is also the primary reason for the significant reduction of near stall condition loss by fillet and endwall profiling coupled flow control. Data mining has revealed that the fillet at the leading edge shouldn’t be too thick under design condition, no matter hub profiling of pressure side near the leading edge concaves or bulges deeply, total pressure loss will increase. In near stall condition, the fillet in middle of the suction side (60% axial chord length) with large thickness can improve flow condition. Moreover, endwall profiling of 60% axial chord length which concaves or bulges deeply is harmful for flow field in both design and near stall conditions, and it should be more cautious to design the profiling here.