Patent ID: 9016132
Filing Date: 2015-04-28
Classification: F01D,G01H,G01M

Abstract:
1. A method of analysing blade displacements detected by a plurality of circumferentially spaced stationary timing probes associated with an assembly of rotating blades mounted on a rotor, the blade displacements corresponding to the times at which the blades pass the respective probes, the method including the steps of: (a) identifying a possible resonant vibration event in the assembly of rotating blades; (b) zeroing the blade displacements on the rotations identified with the resonant vibration event to remove invariant blade displacements; (c) fitting modelled blade displacements corresponding to possible blade vibrational deflections at a plurality of frequencies to the zeroed blade displacements; and (d) characterising the resonant vibration event by identifying at each rotation the frequency having modelled blade displacements which correlate best with the zeroed blade displacements; wherein step (c) includes performing at each individual rotation identified with the resonant vibration event the sub-step of: (c-i) fitting the modelled blade displacements at each frequency to the zeroed blade displacements for a plurality of successive rotations which include that individual rotation.