A mathematical model is developed to predict the suppression of rotating stall in a centrifugal compressor with a vaned diffuser. This model is based on the employment of a control vortical waveform generated upstream of the impeller inlet to damp weak potential disturbances that are the early stages of rotating stall. The control system is analyzed by matching the perturbation pressure in the compressor inlet and exit e owe elds with a model for the unsteady behavior of the compressor. The model was effective at predicting the stalling behavior of the Purdue Low-Speed Centrifugal Compressor for two distinctly different stall patterns. Predictions made for the effect of a controlled inlet vorticity wave on thestability of the compressorshowthat, for minimum controlwave magnitudes, on the order of the total inlet disturbance magnitude, signie cant damping of the instability can be achieved. For control wave amplitudes of sufe cient amplitude, the control phase angle appears to be the most important factor in maintaining a stable condition in the compressor.