Study on Cavitation Bubble Characteristics in Centrifugal Pump Based on Image Recognition

Abstract

In this paper, a cavitation bubble in the centrifugal pump cavitation phenomenon was observed in the analysis and research to explore the characteristics of a cavitation bubble in a centrifugal pump. Through the construction of a visualization centrifugal pump test platform and the observation of a high-speed camera, an image processing method was used to extract the characteristics of the cavitation bubble in the captured results, and the characteristics of the cavitation bubble in the centrifugal pump were analyzed and studied in a quantitative way. The results show that the shapes of the cavitation bubbles in a centrifugal pump can be simplified approximately into an ellipsoid shape, more than 75% of the bubbles have a length–diameter ratio between 1 and 2, and the distribution is relatively uniform. Different working conditions affect the size of the cavitation bubble but have little effect on the shape. The average size of the cavitation bubble under different working conditions was calculated by data fitting. This method, which combines high-speed imaging technology and image processing technology, is capable of observing the behavioral characteristics of cavitation bubbles in centrifugal pump cavitation flow both in detail and intuitively. The new method is provided to describe quantitatively the shapes and sizes of bubbles. It is of great significance in understanding the movement characteristics and manifestations of bubbles during a centrifugal pump’s operation and in the further study of the micro mechanisms of the negative effects of cavitation on equipment performance.