The Impact of Surface Roughness on Axial Compressor Performance Deterioration

Axial compressor deterioration due to removable desposits is a major concern in the operation of gas turbines. It is important to fully understand the flow mechanisms in order to successfully monitor and clean the engine. A test program on the GE J85-13 jet engine quantified the increased surface roughness and the distribution of salt deposits in an axial compressor. The test data showed good agreement with published data for stage performance deterioration. This paper compares the GE J85-13 test data on surface roughness to previously published work on surface roughness in compressors. The effect of surface roughness on the stage scharacteristics is modeled using theory for frictional losses, blockage and deviation. The results are compared to test data. The most significant effect of increased roughness is found to be the variation in the flow coefficient.