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Fluid–structure interactions may impact the precision and reliability of the unsteady flow and rotor deflection investigation in the centrifugal pump. The energy transfer between fluid and solid could disregard due to ignorance of fluid–structure interaction. This study numerically examines a centrifugal pump's unsteady flow and structural characteristics under varied blade numbers. The entropy generation is computed and simulated numerically, considering the distributions of energy loss in the flow field. ANSYS Fluent and Workbench were employed to simulate the centrifugal pump. The elastic structural dynamic equation is used to predict the structure reaction. The shear stress transport k–ω turbulence model was conducted to simulate the fluid domain. The findings indicated that the head and shaft power increased with the increasing blade numbers at the hydraulic performance. The impeller with seven blades reached the maximum efficiency (78.7%), with an increase of 0.27% relative to the original model. Increasing the number of blades reduces pressure fluctuations at the pump output, and the impeller with nine blades shows a minimum value in pressure amplitude (4960.79 Pa). However, it increases the entropy generation (1.42 W/K) of the centrifugal pump. Variations in blade number affect the distribution and the fluctuation of the equivalent stress and the total deformation. The model with a nine blade exhibited minimum values of equivalent stress and total deformation with 5.74 MPa and 0.046 mm, respectively. This work may improve centrifugal pump operating stability by understanding how blade number affects pump flow and structural behavior and visualizing internal energy loss. [ABSTRACT FROM AUTHOR]

Improvement of centrifugal pump performance (i.e., head and flow rate) is the main goal for designers since it plays a significant role in most industrial fields. Low flow rate and pump head cause low productivity in the industry. Centrifugal pumps involve several parameters that influence their performance. Thus, modifying some of these parameters within a reasonable range is significant in the centrifugal pump design. The blade numbers are an essential design parameter for pumps, which heavily affects the pump's characteristics. This article reviews the effects of the blade number variation on the centrifugal pumps' performance and synthesizes the current study status. Three research approaches are summarized: analytical studies, numerical simulation, and experimental measurement research to demonstrate blade numbers' influence and characteristics. This article highlighted unsolved issues and implications for future research based on prior research findings. It is clarified that the performance of the centrifugal pump was significantly affected by the number of blades. With increasing blade numbers head, and efficiency would increase until specific values. The blade numbers have optimum values for pumping liquids at the best performance. The data gathered in this review article are expected to contribute a guideline and reference for future research of centrifugal pump performance. It can help the designers estimate the optimum blade numbers to obtain better performance at the best design point of the centrifugal pump. [ABSTRACT FROM AUTHOR]

Vertical-axis wind turbines (VAWTs) are being reconsidered as a complementary technology to the more commercially used horizontal-axis wind turbines (HAWTs) because of their economical installation and maintenance. The selection of the blade numbers is one of the crucial concerns for VAWTs. This study focuses on the effects of the blade numbers on the fatigue lives of VAWT tower bases subjected to wind loading. Three straight-bladed VAWTs, with the same solidity ratios but different blade numbers, varying from two to four, were designed. The aerodynamic loading incurred by the VAWTs was computed using the corrected double-disk multistreamtube (DMS) model. The dynamic equations of the turbine systems were solved using the explicit central difference method. Then, a fatigue assessment model, including the crack-initiation and crack-propagation stages, was developed for the turbine tower bases. The results indicate that the three- and four-bladed VAWTs always presented better performances than the two-bladed VAWT in terms of the fatigue life. Moreover, increasing the number of blades from two to three improves the fatigue life of the tower base more than increasing it from three to four at lower wind speeds, while the latter is the more effective way to improve the tower-base fatigue life at higher wind speeds.

Vertical-axis wind turbines (VAWTs) are being reconsidered as a complementary technology to the more commercially used horizontal-axis wind turbines (HAWTs) because of their economical installation and maintenance. The selection of the blade numbers is one of the crucial concerns for VAWTs. This study focuses on the effects of the blade numbers on the fatigue lives of VAWT tower bases subjected to wind loading. Three straight-bladed VAWTs, with the same solidity ratios but different blade numbers, varying from two to four, were designed. The aerodynamic loading incurred by the VAWTs was computed using the corrected double-disk multistreamtube (DMS) model. The dynamic equations of the turbine systems were solved using the explicit central difference method. Then, a fatigue assessment model, including the crack-initiation and crack-propagation stages, was developed for the turbine tower bases. The results indicate that the three- and four-bladed VAWTs always presented better performances than the two-bladed VAWT in terms of the fatigue life. Moreover, increasing the number of blades from two to three improves the fatigue life of the tower base more than increasing it from three to four at lower wind speeds, while the latter is the more effective way to improve the tower-base fatigue life at higher wind speeds. [ABSTRACT FROM AUTHOR]