Experimental investigations on the time-variation fouling characteristics in a low-speed axial compressor stage

Fouling on compressor blades is a critical factor contributing to performance degradation in aero-engines and gas turbines, garnering significant attention. To investigate the fouling characteristics on compressor blades over time and operating conditions, accelerated fouling experiments were conducted on a single-stage low-speed axial compressor. The degradation processes of the static pressure rise coefficient and torque efficiency with fouling time were comparatively analyzed under both the design condition (φ = 0.56) and the low mass-flow rate condition (φ = 0.48). This analysis identified the performance degradation characteristics induced by fouling and quantified the blade surface fouling thickness distribution. Finally, flow fields obtained through numerical simulation were used to explore compressor fouling mechanisms. Results showed that compressor performance exhibits a significant nonlinear decay trend with increasing fouling time, with degradation rates being more pronounced during the initial fouling period. At the maximum fouling time (120 min), the attenuation amplitudes of the static pressure rise coefficient and torque efficiency of the compressor reached 9.13% and 6.92%, respectively, at φ = 0.60. Fouling was mainly deposited on the leading edge and blade tip of the rotor, as well as the leading edge and pressure surface of the stator. In addition, compressors operating at low mass-flow rates were more susceptible to environmental contaminants, which not only enhanced the stability of the fouling layer on the leading edge, but also expanded fouling coverage on the pressure surface.