Performance improvement of axial compressor by introduction of circumferential grooves

Abstract

ABSTRACT Casing treatment has been extensively used as a prudent passive flow control means to enhance the stall margin with a little decrease in efficiency. The shape of various grooves has a substantial influence on the controlling effect. In this study, research on the impact of rectangular, fillet and chamfer types rectangular grooves with different tip clearances gap on the performance of casing treatment is carried out using numerical simulation. The performance of different models of grooves with different tip clearance gaps on NASA rotor 37 is investigated by discretizing 3D RANS equations based on the finite volume method. A few numbers of casing grooves models are designed with various tip clearances gap and numerically tested. Rectangular circumferential grooves casing treatment (CGCT) shape and smooth wall casing performances are analyzed. Furthermore, the highest adiabatic efficiencies and stall margins of smooth wall casing, rectangular grooves and fillet, and chamfer types rectangular grooves are compared to evaluate the effect of shapes of grooves on the stability and performance of axial flow compressor with different tip gaps. The adiabatic efficiency of the models 1 ~ 6 decreased by 0.9%, 1.0%, 1.05%, 1.1%, 1.2%, and 1.15% respectively. While the stall margin is increased by 4.4%, 2.5 %, 2.2%, 1.75%, 1.7% and 2.1% for models 1 ~ 6 respectively.