Identification of operational damages of air-turbine engines using visual diagnostics

摘要

The paper presents various types of compressor and turbine scoops damages that are being found in the operating process of air turbine engines. When dividing them, having in mind a genesis of their origin, a special attention has been paid to corrosion and high-temperature erosion, often being a reason for destruction of the entire unit. The in the paper illustrated failures have been found and identified in aircraft gas turbine engines of Polish military aircraft. The specificity of missions performed by military aircraft requires flights to be flown at high speeds, low altitudes, with frequently changing operating ranges, high g-loads, frequently changing loading cycles, etc. That is why failures illustrated with subsequent figures are attributable to mechanical, thermal, and chemical causes. The damages here to described have been illustrated with examples collected during endoscope surveys of LST internal spaces or their post-failure disassembly. The summary points out to the ways and directions of works aiming at early detection of LST turbines units damages, and thus at improvement of their operating safety. Many years of participation in studies, using a visual (endoscopic) method and related to them analysis of LST subcomponents technical condition, allows the authors for making some generalizations, including those related to initiations of the subcomponent damages. This in turn entitles us to conclude that the basic cause of mechanical damage to the compressor and turbine assemblies should be considered as events resulting from the foreign bodies suctioning. This is confirmed by the systematically collected data [8]. In the paper will be presented identifications of compressor unit, turbine unit damages by using a visual (endoscopic) method. Will be presented a lot of examples damages relevant with a lot of operation in military jet engine.