Mechanism analysis of the influence of positional deviation on compressor performance

The compressor is an important part of the aviation gas turbine engine, and as the most important part in the compressor, the aerodynamic performance of compressor blade directly affects the performance of the whole machine. However, with the development of the aviation industry, the geometric shapes of blades have been intricately designed to meet the performance requirements of compressors, placing exceptionally high demands on blade manufacturing. During the manufacturing process, geometric uncertainties arising from machining deviations are predominantly driven by stochastic factors. Their characteristic lies in the fact that increasing the number of experiments does not diminish these variations. The emergence of such variations unavoidably leads to changes in compressor performance, presenting an inescapable challenge. In the realm of machining deviation research, comparative to positional deviations of blades, investigations into other types of blade machining deviations have achieved a more refined level of completeness. To study the influence mechanism of position deviation on the performance of a transonic rotor, the Rotor 37 was chosen as the research subject. A comparative analysis of the overall compressor performance and the rotor flow field was conducted using numerical methods under the condition of reference peak efficiency. The findings indicate that as axial position deviation increases along the axial direction, the performance curve shifts towards decreasing mass flow rate, thereby altering the compressor's range of stable operation. Under the reference peak efficiency condition, axial position deviation affects the positioning of shock waves, although the intensity of shock waves is primarily influenced by the span-resulting in varying changes in loss caused by shock wave and shock wave-boundary layer interference at different span. Axial position deviation also impacts the loss caused by leakage flow and the energy of leakage vortices at the blade tip, subsequently influencing the size of the low-speed region formed after the interference of shock waves and leakage vortices. Additionally, it affects the accumulation of low-energy fluid at the blade tip within the boundary layer under centrifugal force, thereby influencing the interaction between shock waves and boundary layers, as well as the blockage of the flow passage. The conclusions of this paper aim to identify critical positions where positional deviation significantly affects performance to provide guidance for future robust optimization of compressor blades.