Novel bionic humpback whale blade for suppressing cavitation in a centrifugal pump

Cavitation results in increased losses, reduced performance, and blade damage, which seriously affects the safe and stable operation of centrifugal pumps. This study introduces a novel bionic blade design aimed at inhibiting cavitation based on the humpback whale's bumpy tubercles. The study investigates the impact of the geometric parameters of the bionic blade on cavitation, pressure, and vortex distribution. Furthermore, the losses inside the impeller are analyzed using entropy generation theory. The research findings indicate that compared to the original model, the bionic blade exhibits superior performance, with the highest efficiency and head achieved when the amplitude of the bionic blade is 0.08 times the blade outlet width. The head and efficiency of the bionic blade increased by 4.4% and by 2.7%, respectively. The bionic structure changes the flow state of the blade leading edge, leading to a reduction in the vortex near the shroud, a decrease in the low pressure region on the pressure surface of the blade, and a substantial increase in the impeller outlet pressure, reaching 13.6%. Moreover, the disappearance of the vortex on the suction surface of the blade inhibits cavitation and high entropy generation regions. As a result, the vapor volume and total entropy generation in the impeller significantly decrease by 38% and 37.4%, respectively, under severe cavitation conditions.