Assessment of Cavitation Erosion in a Water-Jet Pump Based on the Erosive Power Method.

Ning Qiu,Han Zhu,Jinqing Zhong,Suhuan Wu,Rongsheng Zhu,Yun Long,Qiao Yanxin

doi:10.1155/2021/5394782

Abstract

Cavitation affects the performance of water-jet pumps. Cavitation erosion will appear on the surface of the blade under long-duration cavitation conditions. The cavitation evolution under specific working conditions was simulated and analyzed. The erosive power method based on the theory of macroscopic cavitation was used to predict cavitation erosion. The result shows that the head of the water-jet pump calculated using the DCM-SST turbulence model is 12.48 m. The simulation error of the rated head is 3.8%. The cavitation structure of tip leakage vortex was better captured. With the decrease of the net positive suction head, the position where the severe cavitation appears in the impeller domain gradually moves from the tip to the root. The erosion region obtained by the cavitation simulation based on the erosive power method is similar to the practical erosion profile in engineering. As the net positive suction head decreases, the erodible area becomes larger, and the erosion intensity increases.

Highlights

Compared with traditional propellers, water-jet pumps have the advantages of high propulsion efficiency, good manoeuvrability, and low vibration
Cavitation erosion will appear on the surface of the blades when the pump is operated under cavitation conditions for a long time
The cavitation mechanism in the water-jet pumps was analyzed based on the RANS method and the DCM-SST turbulence model, and the cavitation erosion was predicted based on the macroscopic cavitation theory in this paper

Summary

Introduction

Water-jet pumps have the advantages of high propulsion efficiency, good manoeuvrability, and low vibration. Cavitation erosion will appear on the surface of the blades when the pump is operated under cavitation conditions for a long time It will affect the reliability of the overall system and cause high maintenance costs [8,9,10,11]. Tan et al [12] observed the formation of perpendicular cavitation vortex (PCV) in the impeller of the water-jet pump by experimental method. Wu et al [16] used the particle image velocity measurement method to study the turbulence structure of the tip leakage vortex of an axial water-jet pump. The cavitation mechanism in the water-jet pumps was analyzed based on the RANS method and the DCM-SST turbulence model, and the cavitation erosion was predicted based on the macroscopic cavitation theory in this paper

Experimental Setup

Numerical Simulation Methods

Analysis of Results

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Findings

Conclusion