Influence of Circumferential Groove Casing Treatment on Behavior of Tip Leakage Flow in Low Speed Axial Compressor

－Influence of Axial Location of Groove－

Abstract

In this study, in order to enhance the effect of circumferential groove casing treatment on the improvement of the aerodynamic performance of axial compressor, the influences of axial location of single groove on the flow field and the loss generation in a low speed axial compressor rotor were investigated numerically. Flows in the compressor with and without the groove were computed and then the comparison of computed results clarified following phenomena. The groove weakens the tip leakage flow by the decrease of the blade loading and consequently shifts the interaction position between the main flow and the tip leakage flow toward the downstream. This trend is intensified when the groove is installed at higher blade loading location. Meanwhile, although the groove decreases the loss generation caused by the tip leakage vortex, the total loss generation is increased due to the additional loss attributed to the application of groove.