Impact of key airfoil blade parameters on the internal flow and vibration characteristics of centrifugal pumps

Pressure pulsations and transient fluid forces resulting from unstable internal flow can significantly impact the vibration performance and operational stability of centrifugal pumps. This study delves into the influence of key parameters like airfoil blade thickness, outlet angle, and curvature on the internal flow dynamics and vibration characteristics of these pumps. The research highlights how variations in airfoil blade parameters primarily affect the mid-to-rear regions of the impeller and the volute flow region. By optimizing the outlet angle of the airfoil blades, the curvature radius of the pressure side profile, and the maximum blade thickness within a specified range, the study demonstrates a reduction in flow velocity at the impeller outlet, alteration of flow direction, and mitigation of vertical fluid impact on the volute casing wall. These adjustments effectively decrease the strength and quantity of unstable vortex structures within the pump, leading to a more stable flow regime. Consequently, this optimization minimizes rotor-stator interaction effects within the pump, resulting in decreased pressure pulsations and fluid forces on the volute casing wall, thereby reducing vibration levels. However, deviations from optimal parameters, such as outlet angle coefficient A < 0.46, pressure side profile curvature radius coefficient B < 0.53, and maximum blade thickness coefficient C > 0.11, can lead to an uneven distribution of blade loads, increased radial forces, vorticity at the tongue, and pressure pulsations, ultimately compromising the operational stability of the pump.