Abstract:

In order to quantify the comprehensive impact of multi-type geometric manufacturing tolerances of axial compressor blades on performances, a method of constructing three-dimensional blades with multi-type manufacturing tolerances was designed, and the three-dimensional computational fluid dynamics(CFD) numerical simulations of compressor stage samples at the design point were conducted. Then, the uncertainty quantification analysis and sensitivity analysis were conducted. Finally, the typical results of two blade samples with geometric errors, which have the highest efficiency and the lowest efficiency, respectively, were selected to explore the impacts of their geometric variations on the outlet flow field. The results show that when the compressor stage is working at the design point, the average impact of all real blade manufacturing position, twist, and profile errors within the tolerance on blade performances is negligible. The performances include mass flow rate, total pressure ratio, isentropic efficiency, axial thrust, and torque. However, the torque of rotor relatively changes with a range up to -2.90%-2.30%. The mass flow rate and the total pressure ratio of the compressor stage are most sensitive to the sectional twist of the rotor, while the isentropic efficiency is jointly determined by the twist and axial position of the middle section and the position of the bottom section. With the comprehensive influence of geometric errors, the relative errors of the maximum isentropic efficiency in the two cases are up to +0.31% and -0.46% compared with the original case. The geometric variations change the radial distribution of the relative total pressure loss and the entropy distribution at the rotor outlet obviously, and the flow capacity and the pressurizing ability of blade passage are consequently influenced.

Key words: axial compressor, blade, manufacturing tolerance, aerodynamic performance, uncertainty quantification