Experimental investigation on the effect of fouling-induced surface roughness on the aerodynamic performance of compressor cascades

This study systematically investigates the impact of fouling roughness on compressor cascade performance through wind tunnel tests and PIV measurements. Results show fouling significantly increase aerodynamic loss (65.96% for Ra₃ at Ma=0.4) and reduce stable operating range. The cascade is most sensitive to roughness in terms of the roughness coefficient Crs at i = 0° incidence, while positive incidence angles cause severe work capability degradation. Higher Mach numbers could exacerbate performance deterioration within the studied operating range, with a corresponding risk of inducing a vicious cycle between speed compensation and stability loss. PIV reveals fouling alters loading distribution and intensifies flow separation, elucidating the connection between macro-performance and micro-flow mechanisms.