A model is proposed to analyze the influence of inlet circumferential distortion on axial flow compressor off design performance.The model describes the flow fields in blade free sections using two dimensional

compressible unsteady Euler equations

and replaces each blade row of the multistage compressor with a compressible “actuator disk”.The axisymmetric characteristics of each blade row in the model is directly calculated with the help of same method as in the subsystem with uniform inlet flow.Thus there is no difficulty in the model to give the characteristics of each blade row of the compressor calculated.Attenuation of an inlet circumferential total pressure distortion through a five stage high speed compressor and it's influence on the compressor performance are analyzed in detail.The comparison of the analyzed results with the available experimental data demonstrates that the model is reliable.