The Sensitive Parameter Study of Axial Flow Compressor Fouling

Fouling is an important performance degradation factor of axial flow compressor. Proper fouling sensitive parameter is crucial to more effectively monitor the fouling severity. Currently fouling level and cleaning necessity are judged by the decrease degree of thermodynamic performance parameter from macro point. But simulation research of NASA rotor 37 finds that tip clearance increase also causes the decrease of thermodynamic parameters such as pressure ratio, mass flow, efficiency and output power, so these parameters can’t distinguish fouling and other failure modes. Contaminated particles within air deposited on the blade surface to cause the change of blade shape and surface roughness. But from the definition of roughness, fouling and erosion can’t be distinguished by surface roughness. Finally, blade profile parameters are chosen as sensitive parameter of fouling. At the same time, with the rapid development of measure technology, profile parameter can be measured by combination of laser triangulation method and CMM (coordinate measuring machine). Based on reverse engineering, measure point clouds are reconstructed into three dimensional solid model of fouled compressor. Quantitative research shows that fouling cause increase of total temperature, total pressure and surface friction coefficient, simultaneously effective flow area is decreased, thus thermodynamic performance is degraded.