Research on the Effect of Small Blade Arrangement on the Cavitation Performance of Centrifugal Pumps

This study proposes a novel approach to enhance the cavitation performance of centrifugal pumps with low specific speed by incorporating small blades within the impeller flow channel. These blades are deflected at specific angles at their trailing edges to suppress cavitation and improve pump efficiency. Experimental tests were conducted to assess the external characteristics and cavitation performance of a prototype pump, and the results were compared with numerical simulations. The findings indicate that the addition of small blades has minimal impact on the pump's external characteristics but significantly enhances its cavitation performance. Specifically, the low-pressure regions and areas of high-intensity turbulent kinetic energy within the impeller were reduced. Consequently, the volume of cavitation bubbles and the amplitude of pressure pulsation decreased. Flow field analysis revealed that the modified flow structure is more stable, with reduced vortex intensity. The small blades effectively align disordered turbulent flow lines, thereby suppressing cavitation development.