Synergistic effect of tip winglets and controllable speed casing on compressor stability

This study proposes a novel coupled flow control strategy by integrating compressor blade tip winglet technology with controllable speed casing technology, and investigates its effectiveness in enhancing the stable margin of high-load compressor stages. The results demonstrate that using blade tip winglets alone increases the compressor stage's stable margin by 26.03% at the rotor design speed. When the controllable speed casing technology is integrated with the tip winglet, the stable margin is further improved to 38.86%. The underlying stabilization mechanism primarily involves two cooperative effects: the axial redistribution of blade load in the rotor tip area under the winglet's influence, and the circumferential force generated by the rotating casing segment. This synergistic action modifies the flow trajectory of the tip leakage flow, reduces the intensity of the tip leakage vortex, regulates secondary leakage flow patterns, decreases tip leakage flow rate, and ultimately improves the through-flow conditions in the rotor tip region.