Effects Of Casing Configuration On Post-Stall Performance Of Axial Flow Compressor

A series of stepped tip gap (STG) casing configuration and non-axisymmetric tip clearance (NTC) casing configuration were designed and tested on a low-speed axial compressor with just a single rotor.The experiments showed that, with a steeped tip gap casing configuration, the compressor's total performances, both stable and post-stall performance, would be improved, if the casing had been properly configurated. On the other hand, if nonaxisymmetry emerged in the tip clearance of the rotor, the overall performances of the compressor were degraded. The experiments also showed that stall-unstall hysteresis loops on the performance map of an axial compressor would conveniently be used to analysis the post-stall performances of axial compressors with casing configurations.A one-dimensional , unsteady and compressible mathematic model was set up and applied to simulate the post-stall performance of the axial compressor with variable casing configuration. Based on the model, a C++ program was also developed and executed successfully. Compared with the experimental results, the computational results proved the validity of the model and program developed.