UDC 519.246 © B.G. Kukharenko USE OF SWITCHING KALMAN FILTER FOR OSCILLATION REGIME IDENTIFICATION UNDER COMPRESSOR ROTOR BLADE FLUTTER Compressor rotor blade flutter evolution is under study. <...> The blade oscillation record spectrum is obtained by the segmented Prony method. <...> As shown, the classic Prony method autoregression can be used by itself to identify the blade unstable oscillation regimes in the switching Kalman filter model. <...> The unstable oscillation regime switching is similar to obtained by the segmented Prony method, but the regime switching estimate is less cost from computations point of view. <...> Keywords: compressor rotor blade, blade mode instability, flutter, unstable time-series, the Prony method, autoregression, oscillation regime, the switching Kalman filter. 1. <...> Introduction In compressors, a rotor single blade oscillation induces pressure pulsations of air counterf low, which leads to nearest neighbor oscillations (in theory, produced by a mean aeroelastic force). <...> As result, first frontal stage rotor blades (on the left in fig. 1) can demonstrate an aeroelastic instability (flutter), while the rotor isolated blade in the air counterflow not subject to flutter. <...> As result, a single interblade passage model is sufficient to describe the whole blade cascade oscillations. bending branch exhibit instabilities in the practical range of design parameters and aeroelastic force strength. <...> As shown by experiments, independent of bending to torsion modal frequency ratio, at an air counterflow velocity increase there is no an appreciable tendency to converge the bending and torsion modal frequencies of rotating blade [4]. <...> In real compressors, blades of rotor stages never are Fig. 1. <...> Three stage compressor rotor In paper [3] for blade lumped model under an aeroelastic force, the bending-torsion coupling effect on the f lutter boundary of compressor rotor blade is under study. <...> As shown, it is a torsion branch, which becomes unstable at first. <...> The insensitivity of modal frequencies to a relative air velocity is noted also: the f lutter frequency is within 0.6 percent of the natural frequency of torsion branch in vacuum (pure torsion flutter) [3, 4]. <...> Nevertheless the actual f lutter mode has a bending/ torsion <...>