Observer Design for Axial Flow Compressor

Flow disturbance is the main cause which leads to the instability occurred in aeroengines, and it is an infinite-dimensional quantity that is impossible for a direct online measurement in reality. The unstable flow not only results in a drastic pressure reduction but also can damage to engine's components during the compressor operations. In this paper, we construct a local state observer which can deliver the full information of the flow disturbance by only sensing on an arbitrarily small area at the duct entrance in terms of averaging the flow disturbance, which provides a practical approach for real applications. The proposed observer makes possible in applications by using a feedback control to stabilize the system. The convergent gain is obtained through the approach of operator spectrum theory. Numerical simulations are provided to illustrate the effectiveness of the proposed observer by showing typical types of flow situations for aero-engine compressors.