Study on cavitation flow and high-speed vortex interference mechanism of high-speed inducer centrifugal pump based on full flow channel

Abstract

High-speed centrifugal pumps are crucial in aerospace and petrochemical industries due to their high speed and head. To enhance cavitation performance, the inducer and impeller, which are critical flow components, require specialized design and optimization. This study examines cavitation flow and high-speed vortex interference in a full-channel high-speed inducer centrifugal pump. Analyzing the void volume fraction in the inducer and impeller flow passages under various effective cavitation allowances reveals that as the allowance decreases, void volume increases, and the hump position shifts backward. The study also correlates the static pressure distribution on the inducer blade surface with cavitation states, finding that a decrease in the cavitation allowance leads to an expansion of the low-pressure area on the blade surface, aligning with the cavitation distribution area. This is vital for assessing the inducer's power capacity. Observations of the impeller blade's pressure distribution show that the low-pressure area is concentrated at the inlet of the suction surface, expanding towards the impeller outlet. The bubble volume distribution area matches the low-pressure region. As cavitation progresses, the static pressure in the impeller passage decreases, impacting the impeller's normal operation and performance. Comparing the interference between the cavitation zone and the high-speed zone in the flow channels of the inducer and impeller, it's evident that cavitation increases the low-speed zone area on the velocity contour surface. This results in the appearance of a velocity vector in the low-speed zone, affecting the pump's performance. As cavitation worsens, bubbles adhere to the entire flow channel, causing a significant drop in the pump head and impacting the pump's working efficiency. This paper provides valuable insights into the cavitation flow and high-speed vortex interference mechanisms in high-speed inducer centrifugal pumps, offering significant guidance for their design and operation.