Investigation on the flow characteristics of a centrifugal pump with a fractured leading edge of a single blade

Centrifugal pumps are essential in various industrial applications, and their stable and efficient operation has a direct impact on the overall performance of the system. This study simulates different lengths of fractures at the LE (leading edge) of a single blade to conduct an in-depth analysis of their effects on internal flow and transient characteristics. The study reveals that the most significant effects of blade LE fractures on pump performance occur near a flow rate of 0.8Qd, where the head and efficiency can decrease by up to 6.19% and 3.77%, respectively, compared to the original blades. Blade fractures lead to deterioration of flow on the pressure and suction sides, creating vortices and inducing leakage flow, while entropy production significantly increases in this area. A 230.1% increase in the distribution angle and a 26.6% increase in the maximum radial force reflect changes in the radial force distribution. Also, LE fractures make the wall pressure pulsations stronger at the SPF (shaft passing frequency), and they make the amplitude of the pulsations on the blade surface much bigger at both SPF and 3SPF frequencies. Finally, LE fractures change the way vibrations behave at radial measurement points in both the x and y directions in a big way. The acceleration amplitudes at SPF and 3SPF frequencies go up by 125.8%, 193.1%, and 62.5%, 184.6%, respectively. These findings provide an important theoretical basis for the early warning and diagnosis of blade fracture failures.