METHOD OF STAND TESTS OF TURBO-REACTIVE TWO-CIRCUIT MOTOR Russian patent published in 2019 - IPC G01M15/14 

FIELD: testing equipment.

SUBSTANCE: invention relates to the field of engineering of gas turbine engines, and in particular to the methods of bench tests of turbojet by-pass engines (TRD) with verification of the absence of self-oscillations of engine fan blades. In the bench test method of a turbojet bypass engine in the operating frequency range n_F.PR rotation of the fan rotor, the corresponding subsonic flow of working blades, measure the total pressure P*_IN at the engine input in front of the fan, full pressure P*_F behind the first fan stage in the angular position 0±10° relative to the center line of symmetry of the pylon, consumption G_F air through the fan, temperature T*_IN deceleration flow input of the engine in front of the fan and the frequency n_F fan rotor rotation, calculate the value of π*_ST1 the degree of increase in pressure of the first stage of the fan, calculate the reduced frequency n_F.PR rotation of the fan rotor and the reduced flow G_F.PR air through the fan according to measured values of n_F, P*_F, G_F and T*_IN, compare the obtained value of π*_ST1 with the upper threshold value π*_ST1.UPPER designated as a result of preliminary tests of this type of engine the degree of increase in pressure of the first stage of the fan, depending on the value of G_F.PR in the operating frequency range n_F.PR and according to the result of the comparison of values, the adjustment of the engine operation is carried out, achieving the coincidence of π*_ST1 and π*_ST1.UPPER with constant G_F.PR in the operating frequency range n_F.PR, and only under the specified conditions, the absence of self-oscillations of the fan blades is checked, and if they are absent, the bench tests are completed, and in the case of self-oscillations, the assigned upper threshold π*_ST1.UPPER is adjusted the degree of pressure increase and re-check the absence of self-oscillations of the fan blades.

EFFECT: technical result achieved with the implementation of the present invention is to ensure that there are no auto-oscillations when subsonic flux flows around the working blades as part of bench tests for turbofan engines with a part of the suspension pylon design placed in the channel of the outer contour.

1 cl, 3 dwg