A CFD Study on Cavitating Flow in High-Speed Centrifugal Pumps under Low Flow Rates

Abstract:

Cavitation is one of the most important aspects that need to be considered while designing centrifugal pumps, since it is a major contributor to failure and inefficiency. In order to study the cavitating performance in high-speed centrifugal pumps under low flow rates, the pump named IN-32-32-100 with two different impellers was investigated based on numerical and experimental methods. The impeller case 1 is the impeller with six blades. The impeller case 2 is the impeller with four long and four splitter blades. The research results show that the cavities of two impellers occur at the impeller inlet. The region of developed cavities extends and the volume fraction in the blade passages gradually increases with the decrease of inlet total pressure at the flow rate of 0.5Q_d. The cavities distribute asymmetrically in each blade passage and the vapor fraction of one blade passage is significantly larger compared with them of blade passages. The inner flow of the pump can be effectively improved with more uniform pressure distribution by applying splitter blades. The critical cavitation number of the impeller case 1 and impeller case 2 corresponding to the sudden head-drop point are 3.2m and 3.55m, respectively. Compared with impeller case 2, cavitating performance of the pump with impeller case 1 is better. The numerical results agree well with the experimental data, which shows that the numerical method in the present study can to some extent accurately predict the cavitating development inside the high-speed centrifugal pump.

• Periodical: Advanced Materials Research (Volumes 945-949)
• Pages: 914-923
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.945-949.914
• Online since: June 2014
• Authors: Jian Ping Yuan, Yu Wen Zhu, Ai Xiang Ge
• Keywords: Cavitating Performance, High-Speed Centrifugal Pump, Low Flow Rates, Numerical Simulation

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