The study of wet compression flow control in centrifugal compressors based on leading edge tubercles design

To mitigate the inertial loss caused by injected droplets and enhance the wet compression performance of centrifugal compressors, this study investigates the design of the LET (leading edge tubercle) structure on compressor blades. The objective is to explore the flow control mechanisms and establish design guidelines for the tubercle structure in centrifugal compressor wet compression. The Euler–Lagrange particle tracking method is employed as the numerical approach for two-phase flow, and a bidirectional coupled numerical simulation method is developed to model the interaction between droplets and the airflow. Parametric designs of the tubercle amplitude and wavelength are carried out, and the internal flow field structure of centrifugal compressors with various tubercle configurations is visualized. The study further examines droplet motion, droplet collisions, and water film formation within the compressor. Moreover, entropy generation rate is utilized to quantify the internal energy loss within the compressor, revealing the variations in loss distribution and mechanisms associated with different LET configurations. The results demonstrate that the LET enhances wet compression performance by reducing internal energy loss, with the pressure ratio increasing by up to 5.41% and efficiency improving by up to 1.65% under rated conditions. The tubercle-induced flow disturbances enhance shear forces and vortices, causing the droplet distribution to evolve toward smaller droplets. The distribution peak shifts to the lower diameter range, and the distribution curve transitions from a unimodal to a multimodal form. Additionally, the droplet breakup mechanism shifts from pocket breakup to oscillatory breakup.