TURBOJET ENGINE GAS GENERATOR TESTING METHOD FOR ABSENCE OF HIGH-PRESSURE COMPRESSOR WORKING BLADES SELF-OSCILLATIONS Russian patent published in 2025 - IPC G01M15/14 F01D21/00 

FIELD: aviation.

SUBSTANCE: invention relates to the field of testing aircraft engines, in particular a gas generator of a turbojet engine for the absence of self-oscillations of working blades of a high-pressure compressor, and can be used at bench tests when checking for absence of self-oscillations of "breakdown" type in working blades of high-pressure compressor. Essence of the invention consists in measuring the total pressure behind the compressor first stage, the air flow through the compressor and the rotor speed, calculating the pressure increase degree in the first stage according to the measured values and the reduced air flow rate, assigning an upper threshold of the degree of pressure increase depending on the value of the reduced air flow rate in the operating range of reduced frequencies and determining the value of the size coefficient K_P1 compressor first stage mode according to preset formula. Further, assigning a value of dimensional coefficient K_P1.UP upper threshold value taking into account self-oscillations margin at constant value of compressor rotor reduced speed, comparing obtained values of coefficients K_P1 and to K_P1.UP modes. At K_P1 < K_P1.UP communicating the combustion chamber to the compressed air source, setting the source outlet pressure equal to the total pressure at the compressor outlet, performing the compressed air supply to the generator combustion chamber, increasing the pressure at the output of the bench compressed air source, increasing the flow rate of the compressed air blown into the gas generator combustion chamber and determining the value of the dimensional coefficient K_P1 until its coincidence with specified value of dimensional coefficient K_P1.UP. Under this condition absence of self-oscillations of working blades of the first stage of the compressor is checked, and in case of presence of self-oscillations the tests are repeated.

EFFECT: enlarging technical capabilities of testing method of gas generator of jet turbine engine.

1 cl, 4 dwg