Assessing Energy Loss and Entropy Production in a Centrifugal Pump with Various Impeller Blade Trailing Edges

The centrifugal pump holds significant prominence as a widely adopted power machinery in mechanical industries. This study aims to uncover the influence of blade trailing edges on the energy performance of centrifugal pumps. Sixteen types of blade trailing edge models, including Bezier trailing edges, rounded pressure side, cut suction side, and original blade trailing edges, are examined both numerically and experimentally. Entropy production power and energy loss for each domain with different trailing edge models are computed using entropy production theory and the pressure drop method, respectively. The correlation between them and the interaction of energy loss in various domains are determined through Spearman correlation analysis. Furthermore, the energy loss and efficiency of the centrifugal pump are decomposed and explored. Finally, the impact of different trailing edges on each component of shaft power is analyzed. The study findings indicate that increasing the radius of the trailing edge leads to higher head, while a thinner trailing edge enhances efficiency. Consistent trends are observed in entropy production and energy loss across different blade trailing edges. Modifying the impeller trailing edge significantly affects not only the impeller but also the cavity, diffuser, and outlet chamber, with minimal impact on the inlet chamber. Thinning the blade trailing edge can decrease energy loss and entropy production. Proper design of the blade trailing edge can effectively reduce the pressure pulsation near the impeller outlet in the stator. This study serves as a valuable reference for the design and research of centrifugal pump blade trailing edges.