Авіаційно-космічна техніка та технологія (Jun 2024)
Determining the influence of roughness and tip clearance on the axial multistage compressor characteristics
Abstract
The operation of gas turbine engines inevitably increases the blade roughness and tip clearance in multistage axial compressors. The result is an increase in its thermogasodynamic parameters. The reason for the increase in the roughness of the blades and the tip clearance can be various factors: clogging of the flow part of the compressor (adhesion and deposition of dust on the surface of the blades), erosion due to the arrival of hard sand grains in the flow part, etc. The subject of this study is thermogasodynamic processes in the flow part of a multistage axial compressor, based on the presence of flow part removal. The goal is to develop a methodology for forecasting and researching the influence of the blade surface roughness and increased tip clearance on the overall characteristics of a multistage axial compressor. A twelve-stage axial compressor was used as the research object. The guiding vanes of the first four stages and the inlet guiding vanes depend on the rotation frequency. As a result, it was not possible to investigate the influence of the surface roughness of the blades and the increased tip clearance on the overall characteristics of the multistage axial compressor. The calculation of the characteristics of an axial multistage compressor with simulation of different levels of roughness and increased tip clearance in comparison with its initial values and obtained several indicators of changes in thermogasodynamic parameters and characteristics of the compressor with changes in roughness (ks = 3 μm, ks = 20 μm, ks = 40 μm) was performed. and tip clearance (Δr=1%, Δr=2%, Δr=5%). The scientific and practical novelty of the obtained results arises from the following: the method of calculating the thermogasdynamic parameters and characteristics of an axial multistage compressor has been improved, which makes it possible to evaluate the effect of the roughness of the surfaces of the blades and the increased tip clearance; new data were obtained regarding the change in the compressor characteristics at different levels of roughness and the size of the tip clearance.
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