EA032992B1 - Method for control of a gas turbine engine blade surface - Google Patents

Abstract

The invention relates to engine manufacturing and may be used for control of gas-turbine engine (GTE) blade surfaces. In the course of operation, the exposure to high-temperatures and erosion may lead to a large increase in the blade surface initial roughness (height of irregularities), which results in higher specific fuel consumption and lower efficiency of the GTE. To avoid this, it is necessary to periodically control the condition of blade surfaces during operation. To assess performance characteristics of the GTE blade surfaces, an averaged characteristic of their roughness Ris applied. However, surfaces having drastically different properties may correspond to the same average roughness values, which indicates inadequateness of using the parameter Ras the only criterion for rejection. The invention objective is control of the GTE blade wearing process not only by roughness, but also by the value of subroughness of its surface layer. The objective is achieved by provision of a method for control of gas-turbine engine blades that comprises measuring the geometric parameters of a set of points located near the blade root, in the middle and near the blade tip, i.e. at a distance of 10, 50 and 90% of the blade height, respectively, assessing the parameter value deviation from the acceptable range and either declaring the blade as fit if the parameter value is within the range, or rejecting it if the parameter value is outside the range, wherein, according to the invention, an average height of subroughness irregularities H is measured in the base section 1×1 μm (1,000×1,000 nm), and in case of H≤14 nm and roughness R=0.1-0.5 μm, the blade is considered fit for further operation.