EFFECT OF COMPRESSOR BLADES’ OPERATIONAL DAMAGES WITHIN AN AIRCRAFT GAS-TURBINE ENGINE ON ITS PERFORMANCE

Damages of compressor blades caused by foreign objects (FO) or bird strike result in a change in the configuration of blades profiles and a decrease in their structural strength. Depending on the damage extent of the compressor blades, as well as on secondary damages and destructions of the structural components of gasturbine engines (GTE), accidents or emergencies may occur. A decrease in the structural strength of damaged blades is taken into account via chippings' rating. The effect of compressor blades' damages on its operational efficiency is not specified. A change in the configuration of the damaged blades' profiles leads to a change in the flow character, which, in turn, may lead to deterioration of effectiveness of the compressor operation and its characteristics as a blade unit. This research is aimed to estimate some types of operational damages of the compressor blades and their possible effect on the effectiveness of the compressor operation as a blade unit. A change in the effectiveness of the compressor operation as a blade unit was estimated based on the analytical method and via compressor operation simulation using gas dynamics numerical methods, which are based on the computational fluid dynamics (CFD) analysis. The analytical estimation of a change in the airflow through the blade passage for the blade with a damaged leading edge in the form of chipping and the results of CFD analysis have shown a possibility of a change in the effectiveness of the compressor operation as a blade unit and deterioration of the compressor characteristics. A substantial change in the compressor characteristics in case of the damaged blades occurs only within a certain range of rotor speeds and for large damages.