03.1 - Aerodynamics – CFD Methods and Validation
APPLICATION OF A SKEWED-SLOT CASING TREATMENT IN A HIGH-LOADING AXIAL-CENTRIFUGAL COMPRESSOR
H.-L. Jin, China; D.-B. Qiu, China; Y.-Q. Yin, China; X.-Q. Zou, China
A skewed slot casing treatments (CT) was applied to a high-loading axial-centrifugal compressor which aims at improving stall margin with little penalty in efficiency. Steady state numerical simulation and test method were used to investigate the effects of the casing treatment on the stall margin of the compressor. The numerical results show that the operating range of the compressor with casing treatment from 60% to 100% corrected speed increases effectively compared with the solid wall case. At the same time the adiabatic efficiency penalty is controlled within 0.3% point at design speed. The test results verified the effects of casing treatment on the stall margin and efficiency of the compressor and have a good agreement trend with the computation results. Under the influence of the CT, the fluid exchange between rotor passage and CT slots. At near stall conditions the injection of energized fluid out of the CT slots decrease the incidence angle of the rotor tip, push the flow separation to the downstream of passage in the tip region and hence delay the onset of rotating stall.