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

FIELD: engines and pumps; test equipment.

SUBSTANCE: invention relates to the field of engineering of gas turbine engines, and in particular to the methods of bench tests of turbojet bypass 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, corresponding to the supersonic flow of working blades, measure the total pressure P*_IN the engine inlet in front of the fan, full pressure P*_F behind the first fan stage in the angular position 180±30° relative to the center line of symmetry of the pylon, G_F consumption air through the fan, temperature T*_IN deceleration flow into the 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 a lower threshold value π*_ST1.LOWER assigned 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.LOWER 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 lower threshold π*_ST1.LOWER is adjusted the degree of pressure increase and re-check the absence of self-oscillations of the fan blades.

EFFECT: technical result consists in ensuring verification of the absence of self-oscillations in supersonic flow around working blades as part of bench tests of turbojet bypass engines with a part of the suspension pylon design part placed in the channel of the outer contour.

1 cl, 3 dwg