Effects of modified micro-vortex generators on aerodynamic performance in a high-load compressor cascade

Abstract

In the current study, the effects of micro-vortex generators on the flow characteristics of a high-load compressor cascade are investigated, and four types of micro-vortex generators including “rectangular,” “curved rectangular,” “trapezoidal,” and “curved trapezoidal” are considered and named VGR, VGCR, VGT, and VGCT separately. The calculated results show that a rising reverse flow region, which is considered a main reason for occurring stall at +8° incidence, collapses rapidly from the leading edge in the cascade. Therefore, the micro-vortex generators are all mounted on the end-wall in front of the passage to suppress the development of the secondary flow, and the stall occurrence is delayed from +8° to +11° incidence by applying VGCT. At the design condition, the VGT can make the total pressure loss decrease by 0.54%. The modified micro-vortex generators show an obvious superiority when the range of incidence is between +3° and +8°. At the stall condition, the VGCT can make the total pressure loss decrease by 9.36%. Moreover, the reduction of the secondary flow loss is considered a main goal of the adoption of micro-vortex generators which is an achievement for decreasing the total pressure loss, and the highest reduction of the secondary flow loss reaches 34.6% at the stall condition in the cascade with VGCT.