Parametric Study of Corner Separation Control in a Compressor Cascade Using Endwall Blowing

In this study, a parametric experimental investigation was conducted to explore the optimal steady endwall hole blowing configurations for managing corner separation in compressor cascades. Parameters such as injection location, injection momentum, and injection skew angle were investigated. A self-developed oil-flow visualization technique was employed to elucidate the flow control mechanisms of endwall blowing, while a five-hole probe traverse was used to reveal the impact on loss characteristics. The results indicate that the streamwise vortices induced by the jets entrain low-energy fluid near the endwall, moving contrary to the transverse flow in the blade passage, thereby effectively alleviating corner separation. With increasing jet amplitude, interactions between the jet flow and the mainstream flow create new high-loss regions, diminishing the effectiveness of flow control. Moreover, increasing the jet skew angle can effectively enhance the intensity of the streamwise vortices, better suppressing the migration of low-energy fluid. However, its interaction with the endwall boundary layer can lead to an increase in passage vortex intensity, resulting in additional high-loss regions. Careful consideration of this loss redistribution is necessary when designing control strategies with endwall hole blowing.