Solid particle erosion is a serious issue in centrifugal pumps that may result in economic losses. Erosion prediction in centrifugal pump is complex because the flow field inside it is three-dimensional (3D) unsteady and erosion can be affected by numerous factors. In this study, solid particle erosion of the entire centrifugal pump for liquid–solid flow is investigated numerically. Two-way coupled Eulerian–Lagrangian approach is adopted to calculate the liquid–solid interaction. The reflection model proposed by Grant and Tabakoff and the erosion model proposed by the Erosion/Corrosion Research Center are combined to calculate the erosion rate and predict the erosion pattern. Results show that for the baseline case, the inlet pipe is the least eroded component, whereas the impeller is the most eroded component. The highest average and maximum erosion rates occur at the hub of impeller. The most severe erosion region of a blade is the leading edge with a curvature angle that varies from 55 deg to 60 deg. The most severe erosion region of a volute is in the vicinity of a curvature angle of 270 deg. The impeller erosion pattern, especially the middle part of the hub and the vicinity of the blade pressure side, can be greatly influenced by operation parameters, such as flow rate, particle concentration, and particle size.

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The performance and service life of centrifugal pumps can be influenced by the clocking effect. In this study, 3D numerical calculations based on the k-omega shear stress transport model are conducted to investigate the clocking effect in a centrifugal pump. Time-averaged behavior and transient behavior are analyzed. Results show that the optimum diffuser installation angle in the centrifugal pump is [Formula: see text] due to the minimum total pressure loss and radial force acting on the impeller. Total pressure loss, particularly in the volute, is considerably influenced by the clocking effect. The difference in total pressure loss in the volute at different clocking positions is 2.75 m under the design flow rate. The large total pressure loss in the volute is primarily caused by the large total pressure gradient within the vicinity of the volute tongue. The radial force acting on the impeller is also considerably affected by the clocking effect. When the diffuser installation angle is [Formula: see text], flow rate fluctuations in the volute and impeller passage are minimal, and flow rate distribution in the diffuser passage is more uniform than those in other diffuser installation angles. Moreover, static pressure fluctuations in the impeller midsection and the diffuser inlet section are at the minimum value. These phenomena explain the minimum radial force acting on the impeller. The findings of this study can provide a useful reference for the design of centrifugal pumps.

Local entropy generation is derived from the second law of thermodynamics, which can directly identify the source of irreversible dissipation and learn more about the physical mechanism of performance degradation. Zwart cavitation model is modified to clarify the rapid head drop of a cavitation flow within a test centrifugal pump, and it is used to simulate the cavitation flow. Local entropy generation method is used to analyze the cavitation flow with varying net positive suction head. The magnitude of entropy generation in different types and regions is compared. Spatial distribution of turbulent and near-wall entropy generation are analyzed. Results show that the modified Zwart cavitation model can better capture the cavity morphology and its evolution. Turbulent and near-wall entropy generations, which mainly concentrate on the impeller, have a large proportion of total entropy generation. The rapid increase in fluctuating velocity entropy generation near the impeller blade pressure side and near-wall entropy generation near the trailing edge of the impeller blade are the main reasons for the rapid head drop within a test centrifugal pump. The sources of turbulent and near-wall entropy generation are vortex and shear stress, respectively.