Performance Deterioration of Axial Compressors Due to Blade Defects

During flight operation the engine swallows sand or other hard particles usually from the runway. Passing through the compressors they will damage the blades, erode the coating and deteriorate seals. The submitted paper presents some measurements, which show the effect on compressor performance due to the most important and frequent defects. The investigation - conducted at high pressure compressors - includes tests with reworked blades at leading and trailing edges, rounded rotor tips and increased tip clearances. The results are summarized in easy to handle correlations, which enables the user to estimate the deterioration and to fix repair rules within the allowed performance loss range.