Blade Wrap Angle Impact on Centrifugal Pump Performance: Entropy Generation and Fluid-Structure Interaction Analysis

The centrifugal pump is a prevalent power equipment widely used in different engineering patterns, and the impeller blade wrap angle significantly impacts its performance. A numerical investigation was conducted to analyze the influence of the blade wrap angle on flow characteristics and energy distribution of a centrifugal pump evaluated as a low specific speed with a value of 69. This study investigates six impeller models that possess varying blade wrap angles (95 degrees, 105 degrees, 115 degrees, 125 degrees, 135 degrees, and 145 degrees) that were created while maintaining the same volute and other geometrical characteristics. The investigation of energy loss was conducted to evaluate the values of total and entropy generation rates (TEG, EGR). The fluid-structure interaction was considered numerically using the software tools ANSYS Fluent and ANSYS Workbench. The elastic structural dynamic equation was used to estimate the structural response, while the shear stress transport k - omega turbulence model was utilized for the fluid domain modeling. The findings suggest that the blade wrap angle has a significant influence on the efficiency of the pump. The impeller featuring a blade wrap angle of 145 degrees exhibits higher efficiency, with a notable increase of 3.76% relative to the original model. Variations in the blade wrap angle impact the energy loss, shaft power, and pump head. The model with a 145 degrees angle exhibited a maximum equivalent stress of 14.8 MPa and a total deformation of 0.084 mm. The results provide valuable insights into the intricate flow mechanism of the centrifugal pump, particularly when considering various blade wrap angles.