The response of an axial compressor to unsteady disturbances

The disturbances of flow in a uniform duct are examined, taking into account a disturbance which is sinusoidal in time. The equations of motion for a plane disturbance with blade forces represented by body forces are considered along with the stage configuration of the compressor and the temperature rise for two-dimensional flow through the stage. An investigation is conducted for the case in which the disturbances are restricted to small amplitudes about the design operating condition for all points within the compressor. The three independent solutions of the disturbance equations obtained for the system of compressor and associated inlet and exit ducts can be used with three arbitrary constants to satisfy three external conditions.