Effect of the Inclined Part Length of an Inclined Blade on the Cavitation Characteristics of Vortex Pumps

Abstract

To study the effect of the length of the second inclined section of the inclined vane on the vortex structure and pressure distribution inside a vortex pump, this paper uses a combination of numerical simulations (CFD) and experimental verification methods to analyze the static pressure distribution of the internal flow field and the volume fraction distribution of the impeller bubble at different total inlet pressures as well as to analyze the volume and streamline of the distribution of the impeller bubble of the vortex pump at different instants. The results show that as the length of the second inclined section of the inclined vane increases, both the low-pressure area and the volume fraction of the vapor bubbles inside the impeller of the vortex pump increase, and the resistance to cavitation becomes worse. When the total inlet pressure of the impeller is low, a large number of vortices will be generated inside the flow channel of the vortex pump, leading to vortex cavitation; the longer the length of the inclined section, the larger the velocity gradient of the fluid and the more serious the phenomenon of deliquescence, leading to more intense cavitation, while a shorter inclined section length can effectively improve the anti-cavitation performance of the vortex pump.

Keywords

• vortex pump
• cavitation
• inclined part
• bubble
• streamline