Study of uncertainty of measuring geometrical parameters of gas turbine engine compressor blade profiles

Abstract

Compressor blades are among the numerous and complicated parts of gas turbine engines. A freeform surface of compressor blades is characterized by a complex of parameters distinguishing the geometry of their individual sections. The paper presents a model of calculating a complex of geometric parameters of blade profiles by a measured array of points. A method of estimating the uncertainty of measurement of a set of geometrical parameters with the use of coordinate measuring machines is developed. Software algorithms have been designed for the implementation of the proposed models and methods. The paper presents the results of analyzing errors of measurement of a set of geometrical parameters of the gas turbine engine compressor blade airfoil. We obtained the probabilistic characteristics of arising errors for three cross sections of the blade airfoil. The proposed models and algorithms for computing a complex of geometric parameters of the measured profiles by an array of points can be applied to software for measuring machines.

Keywords

• coordinate measurement
• compressor blade
• freeform surface
• section
• complex of geometrical parameters
• model
• interval estimate of uncertainty