Авіаційно-космічна техніка та технологія (Aug 2024)
Creation of a built-in torque measurement on the fan shaft of a turbofan engine
Abstract
One of the main problems in the development of turbofan engines with high and ultra-high bypass ratios is the design and testing of fans. Increasing the efficiency of fans of engines of the specified class requires solving many complex interrelated problems in the fields of gas dynamics, materials science, strength, vibration analysis, and technology. One of these tasks is to determine the fan characteristics based on the results of its tests. The subject of this study is the development of a built-in fan shaft torque meter, which consists of hardware and software-algorithmic parts. The goal was to determine the torque in all engine operating modes typical of the fan characteristic tests. Tasks considered in the work: substantiation of the need to create a built-in torque meter to provide bench tests to determine the characteristics of the fan; construction of the design of the hardware part of the torque meter with minimal modifications of engine parts; description of the thermal model of the shaft in the basic mode of engine operation; development of a methodology for determining the parameters of the boundary conditions of shaft heat exchange in off-design engine operating modes; formation of the methodological part of the torque meter integrated into the structure of the engine. For this purpose, the methods of mathematical finite element modeling of the temperature and deformed states of structural elements, as well as the theory of heat exchange, are used. Scientific and practical novelty: a constructive modification of the fan shaft is proposed, which ensures the installation of a toothed inductor and the implementation of a large measurement base, which increases accuracy; a mathematical finite element model of the shaft is formed, which ensures the connection between the torque and the twist angle; it is proposed to use the methods of the theory of similarity to determine the relationship between the parameters determining the conditions of heating and cooling of the shaft, with the measured parameters of the working substance in the gas flow duct of the engine; the structure of the methodological part of the torque meter built into the structure of the engine rotor is formed.
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