Study on the trajectory of tip leakage vortex and energy characteristics of mixed-flow pump under cavitation conditions. (1st January 2023)

• Record Type: Journal Article
• Authors: Li, Wei; Liu, Mingjiang; Ji, Leilei; Li, Shuo; Song, Rui; Wang, Cheng; Cao, Weidong; Agarwal, Ramesh K.
• Is Part Of: Ocean engineering. Volume 267(2023)
• Publication Date: 2023-01-01
• Subjects: Mixed-flow pump -- Tip leakage vortex (TLV) -- Energy characteristics -- Output power -- Cavitation; Ocean engineering -- Periodicals; Ocean engineering; Periodicals; 620.4162
• DOI: 10.1016/j.oceaneng.2022.113225
• Languages: English
• ISSNs: 0029-8018

Abstract

Abstract: To investigate the mechanism of tip leakage vortex (TLV) and energy loss caused by pump cavitation. The SST k-ω turbulence model coupled with the Reynolds-averaged Navier-Stokes equations, combined with the homogeneous flow cavitation model is employed. And the accuracy of the numerical simulation is verified experimentally. The results show that the cavitation intensity seriously affects the load distribution on suction side (SS), and the variation pattern of the low-pressure area distribution on SS is related to the cavitation location. As cavitation deteriorates, the working capacity of the impeller is weakened and the guide vane is also affected, resulting in a sharp drop in the energy performance of the pump. The malignant cavitation becomes the main reason for the decreasing head and unstable operation of the mixed flow pump. Cavitation deterioration reduces the output power of the impeller, and the power distribution characteristics are affected by the degree of cavitation. Malignant cavitation leads to increased frictional and turbulent dissipation losses and increased total energy loss, resulting in a decrease in the effective energy obtained, leading to a decrease in the overall pump performance. The results can provide theoretical reference for improving the cavitation performance of the pumps. Highlights: Cavity alters the structure of TLV, obstructing the impeller passage and causing efficiency loss. Malignant cavitation results in the creation of secondary TLV in the impeller passage. Friction loss is the primary source of impeller energy loss, which worsens as cavitation increases. Malignant cavitation is the main reason for pump head reduction and unstable operation.