Influence of Parametric Modeling of Tip Winglets on the Stable Operating Margin of the Stage 37 Compressor

Abstract

In this study, a novel tip winglet structure was proposed and applied to NASA Stage 37, aiming to regulate leakage flow at the rotor tip while reducing additional weight caused by installing tip winglets. A parametric design approach was employed, providing general design guidelines for the parametric modeling of tip winglets. Tip winglet configurations were determined by adjusting the extension coefficient of the pressure surface and the contraction of the suction surface. By fixing the pressure surface extension coefficient and suction surface contraction amount, the effects of these parameters on the performance of the compressor were analyzed. The results indicated that the pressure-side tip winglet effectively weakened tip leakage vortex strength, reduced interference between shock wave and tip leakage vortex, lowered leakage flowrate, and increased the axial momentum of the leakage flow, thus expanding the main flow range. As the extension coefficient of the pressure-side tip winglet increased, the low-energy fluid blockage caused by tip leakage vortex fragmentation was gradually alleviated. Additionally, the tip winglet's regulation of the upstream rotor flow field reduced stator suction surface separation, thereby enhancing compressor efficiency. A moderate contraction of the tip winglet's suction surface improved the stabilizing effect of the tip winglet, whereas excessive contraction exacerbated suction surface separation. The pressure-side tip winglet configuration, with an extension coefficient of 6 and a suction surface contraction of 30%, increased the compressor's stable operating margin by 26.32% at the design speed.