METHOD FOR DETERMINING FREQUENCY OF FORCED OSCILLATIONS OF IMPELLER AS PART OF TURBO-MACHINE STAGE Russian patent published in 2015 - IPC G01M15/14 

FIELD: measurement equipment.

SUBSTANCE: invention is used for per-unit development of aircraft engines at bench tests, namely development of impellers of turbines and wheels of compressors. At implementation of a method for determining frequency of forced vibrations of impeller (I), number of I blades and number of blades of guide unit (GU) or nozzle diaphragm (ND) of the turbo-machine stage is determined. The turbo-machine is changed over to design mode of operation and rotation frequency of I is measured. With that, the turbo-machine stage is represented in the form of a mechanical generator consisting of GU or ND and I, which is rotated in the fluid medium flow (air or gas). Frequency of forced I vibrations is determined as frequency f of forced vibrations of the mechanical generator by the following formula: f=kn+b, where k - coefficient depending on structural features of the generator, which varies in the range of 0.8 to 1.5; n - I rotation frequency; b - an integral value proportional to the number of blades.

EFFECT: reduction of time costs for tests at determination of frequencies of forced vibrations of the turbo-machine impeller.

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