Авіаційно-космічна техніка та технологія (Aug 2020)
THE EXPERIMENTAL-RATED METHOD OF STYDYING OF WIDE-CHORD FAN OF THE AIRCRAFT ENGINE FOR THE ABSENCE OF FLUTTER
Abstract
The main gas-dynamic parameters are considered for studying of the absence of flutter wide-chord fan of aircraft engine. The experimental-rated method is proposed to confirm the absence of flutter on the fan in the entire operating range of the aircraft engine. The method is based on experience in the design and development of aircraft engine fans. The method proposes the limitations of the study area of operation of a wide-chord of the aircraft engine fan. The method shows the boundaries of the possible operation of a wide-chord of the aircraft engine fan, taking into account the limitations of the studied range for the research and development of the testing. The aircraft flight parameters were processed with the control of the absence of flutter using pressure pulsation gauges. The results of processing the studied flight parameters are generalized and systematized. A technique for graphically depicting of the main controlled parameters of the method in a two-dimensional and three-dimensional setting is shown, indicating the boundaries of the possible range of operation, the wide-chord fan of the aircraft engine under study, taking into account the reserves of pressure and temperature. To verify the method, the test points of the fan are graphically showed in a thermal vacuum chamber of a similar sized fan of an aircraft engine, which, as the figures show, lie near the boundaries proposed in the method. It is proposed to use the studied points with a proven absence of flutter for verification of computational models using software systems and methods, for calculating the absence of flutter, taking into account the limits of possible operation defined in the method. The proposed boundaries of the studied ranges will significantly reduce the list of tests at the flying laboratory and the number of design points, which will allow us to make the best option for checking the absence of self-oscillations of the aircraft engine fan by the experimental-rated method in Ukraine without using a thermal pressure vacuum chamber and flying in hot and cold conditions.
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