Applications of linearized flow theory to axial compressors with asymmetric inlet flows

An analytical investigation was undertaken to determine the applicability of a two-dimensional linearized flow theory to axial compressors with severe asymmetric distortions in the approach flow. Using the assumption of zero axial gap between blade rows, the simplified theory was applied to three compressor configurations: an expanded single stage, a normal single stage and a three-stage configuration. The three-stage configuration was analyzed for two values of the mean flow coefficient and at two radial positions. The simplified theory was not adequate for describing experimentally determined total pressure profiles in an expanded single stage subjected to strong asymmetric inlet flows. The theory gave good agreement with experimental data for a normal single stage subjected to small asymmetric inlet disturbances. Application of the simplified theory to a three-stage compressor with severe peripheral distortions in the inlet flow showed that good agreement could be obtained between theoretical and experimental total pressure profiles. However, the loss coefficient required to attain this agreement resulted in theoretical predictions for other flow functions which were in error by as much as 50 per cent at the circumferential position corresponding to maximum flow distortion. The present theory is capable of providing fair qualitative agreement between theory and experiment for axial compressors with severe asymmetric inlet flow distortions. However, this simplified theory does not simulate the flow processes in such compressors accurately enough to provide good quantitative agreement