Generating Coupled Total Pressure and Swirl Distortions Using S-duct Plate

Abstract The S-duct plate, consisting mainly of a baffle plate and an S-shaped duct, is designed to generate coupled total pressure and swirl distortions. The flow distortions generated using 94 S-duct plates are experimentally investigated using both steady and dynamic probe rakes. Typical coupled total pressure and bulk or paired swirl distortions, are generated by adjusting the circumferential locations of the baffle plate. The swirl vortices may exist in fully developed or underdeveloped states, which affect the characteristics of the coupled total pressure and swirl distortions. Owing to the interactions between low-energy fluid and swirl vortices, the patterns of coupled total pressure and swirl distortions are more complex than those of individual total pressure distortions. Using linear regression models, the correlations between flow distortion intensities and the geometrical parameters of the S-duct plates are established and can be used to design S-duct plates at the preliminary stage.