System identification modeling of rotors behaviour

The prediction of the rotor behavior in its turbo machine final housing is a crucial problem for turbo machinery manufacturers and very complex to solve using classical approaches. The authors, in other works, proposed an innovative method for the determination of a transfer function (MTF) between the rotor responses on a balancing machine (HSB) and on turbo machinery (SP). The proposed method uses a particular formula (MTF), calculated with a black/box approach and based on the application of the theory of System Identification. MTF was determined by a regression analysis of the responses in HSB and SP of 10 rotors; subsequently it was tested and validated on other 15 rotors. The results demonstrate that the proposed MTF simulates a rotor behavior in SP with a satisfactory overlapping of the measured output. In the last presented works, only some results were shown. In this paper all results on prediction and simulation of rotors behavior are presented. An analysis on all graphs allows underlining the repeatability of the proposed method.