Parametric study of rotor tip squealer geometry on the aerodynamic performance of a high subsonic axial compressor stage

Abstract

Rotor with tip squealer is often used in axial compressor of aircraft engine; however, its effect on the aerodynamic performance of axial compressor is not well understood. The purpose of this paper is to numerically investigate the effect of squealer on the performance of a 1.5-stage axial compressor. In comparison with flat tip, suction and pressure side squealers (SSS and PSS) with different height and thickness are implemented on the rotor blade of the compressor stage. Numerical result shows that pressure ratio is increased slightly under different working conditions with SSS. At the reference working point (RWP), SSS helps to increase mass flow while PSS reduces both mass flow and efficiency. Detailed analysis indicates that blade tip loading rises due to SSS while PSS introduces more losses in the tip region. When squealer is used, the amount of tip leakage flow stays almost unchanged, while vortex trajectory and distribution of leakage flow within tip gap are different. PSS enhances tip leakage flow near the leading edge, which makes the mixing of tip leakage flow and main flow faster and stronger.