Comparative Study of the Performance Improvement of an Axial Compressor with a Micro-Vortex Generator and a Suction Slot

Abstract

Flow control methods have been gradually applied to improve the flow field characteristics of axial compressors. However, most of the current research is focused on the cascade, and few studies have taken a compressor as the research object. Therefore, a 3.5-stage transonic axial compressor is adopted to explore the characteristics of different flow control schemes. The effects of the micro-vortex generator (MVG), segmented boundary layer suction (BLS), and combined technology (COM) on the MVG and BLS are compared by the numerical simulation method. The research results are summarized as follows. The excessive accumulated low-energy fluid in the blade passage induces the occurrence of a corner stall in the last stage stator of an axial compressor. At this time, the compressor can still work, but the performance has accelerated deterioration. The flow characteristics are effectively improved when the MVG is introduced, the stall margin improvement ΔSM and the peak efficiency improvement Δηe of the last stage are 2.1% and 1.02%, respectively. Moreover, the BLS shows advantages in removing the three-dimensional reverse flow and decreasing the total pressure loss compared with the MVG, the ΔSM of the last stage is 2.69%, and the Δηe is 1.83%. When the combined technology is applied, it shows a significant advantage in delaying the occurrence of a corner stall, and the stall margin of the last stage is improved by 2.71%. Based on a quantitative analysis method using loss sources, the three flow control schemes show significant advantages in reducing the secondary flow loss sources and the wake loss sources. Above all, the BLS shows significant advantages in reducing the total pressure loss, and the COM shows an advantage in expanding the stable operating range. The research results will provide a reference for studies of flow control methods related to reducing flow losses and widening stability margins.