Experimental simulation of fouling effects in a four-stage low-speed axial compressor: Fouling distribution and performance changes

The accumulation of particulate contaminants on compressor airfoils constitutes a critical operational challenge for gas turbine engines, inducing progressive aerodynamic performance degradation. To explore the susceptibility of different regions on the blade surface of axial flow compressor to micrometer-sized particles, accelerated fouling experiments were conducted on a four-stage highly-loaded axial compressor. Performance parameters, including static pressure rise and torque efficiency, were analyzed pre- and post-fouling. Non-contact blue light scanning was used to determine fouling distribution and thickness. Results revealed substantial performance deterioration post-fouling, manifesting as 6.8% reduction in stage static pressure rise and 8.9% decrease in torque efficiency at large flow coefficient condition (φ = 0.73). The performance degradation was mainly attributed to fouling on the leading-edge and pressure surface of the blade, where the maximum fouling thickness reached 0.28 mm. Additionally, the susceptibility of the fouling is influenced by complex three-dimensional flow structures—particularly enhanced accumulation in regions affected by tip leakage vortices and corner separation zones.