The synergistic effect between compound lean and aspiration on aerodynamic performance in compressor cascades

In this paper, the synergistic effect between compound lean and aspiration on the aerodynamic performance of compressor cascades is discussed. Preliminary experimental data verify the accuracy of the computational fluid dynamics method adopted, and a thorough study on reciprocal effect among lean angle, aspirated flow fraction and aspiration streamwise location is conducted. The calculations show that, due to the shorter streamwise length of the re-grown boundary layer against adverse pressure gradient, the aspiration location located farther downstream from the leading edge can minimize the loss of the blade passage flow. With the application of blade lean, which is similar to the flow control mechanism in the unaspirated cascades, an increase in pressure at the suction surface corner is used to migrate the low momentum fluid from the corners towards the midspan of the suction surface. Meanwhile, the reduced aspirated flow velocity and the improved favorable pressure gradient in the lean anterior plenum can reduce the entropy rise through the plenum. Simultaneously, the suction power required in the blade passage flow is reduced with blade lean, while the suction power for the aspirated flow through the plenum shows the opposite trend.