Parametric study of hole location and angle in hole-blade-treatment on a transonic compressor

Methods for increasing the operating range in compressors are classified into two categories: active and passive. Among the passive methods, one can mention casing treatment, recirculation, tip squealer, and so on. This study reports on the effect of hole blade treatment on the stability and endwall flow field of a high-speed compressor rotor. The hole blade treatment method can achieve a similar operating range compared to casing treatment, while exhibiting lower total pressure ratio and efficiency loss. Furthermore, the hole-blade treatment can achieve a comparable operating range to recirculation methods by sucking passage shock downstream and reducing blade loading. However, the selection of the hole design parameters is of great importance, as an incorrect choice will not only fail to expand the operating range, but may even lead to its reduction. The parameters investigated include hole angle, location, and its chordwise diameter. Simulation results indicate that the location, angle and diameter of the holes play a crucial role in rotor operating range.