A Novel Decomposition Method for Manufacture Variations and the Sensitivity Analysis on Compressor Blades

Abstract

A high accuracy blade manufacture variation decomposition method was proposed to decompose the manufacture variations of compressor blades to systematic variation and non-systematic variation, which could help to clearly quantify the statistical characteristics of the effect of manufacture variations on the blade aerodynamic performance and to guide the modeling of manufacture variations in geometric uncertainty quantification and robust design studies. By conducting the decomposition of manufacture variations with 100 newly manufactured blades of a high-pressure compressor, it was found that the systematic variation could be modeled by using seven representative blade geometry design parameters well and the mean value of the non-systematic variation, which is determined by using the difference between the measured blade and systematically reconstructed blade, is close to zero. For the standard deviation of decomposed manufacture variations, the non-systematic variation accounts for about 40% of the whole, indicating that the systematic variation is the major component of the manufacture variation. However, based on statistical analysis and sensitivity analysis of the effects of the two types of manufacture variations on blade aerodynamic performance, it was found that the mean deviation of the blade loss mainly derives from systematic variations, and the loss dispersion caused by non-systematic variations is significantly greater than that caused by systematic variations. Furthermore, the blade loss at the high incidence angle is most sensitive to the inlet metal angle which belongs to the systematic variation. Meanwhile, the non-systematic variation near the leading-edge is the most sensitive, and it contributes to most of the performance disperse but only accounts for a geometric variation of about 0.45%.