HIGH-SPEED COMPRESSOR SURGE WITH APPLICATION TO ACTIVE CONTROL

This paper discusses the mechanics of surge as observed on the high-speed axial compressors of modern aero-engines. It argues that the initial stage of the instability consists of a high-amplitude blast wave that develops nonlinearly from a small-scale disturbance and is thus not correctly described by traditional small perturbation stability theories. It follows from this that active control schemes of the global type may be inappropriate, since to be effective, control would have to be applied in a short time and in a very detailed manner, requiring a large number of transducers and actuators. Active control may, though, be effective in controlling the disturbances that grow into the above blast wave and in the control of other phenomena such as rotating stall, given an adequate number of transducers.