Study of Thermodynamic Cavitation Effects in an Inducer

To investigate the effect of water temperature on the cavitating flow characteristics inside a rotating inducer, a series of experiments have been conducted based on a model inducer in a newly developed visualization test facility using heated water as a working fluid. A practical image processing method was developed to analyze the visualization results quantitatively. The cavitation tests were carried out both before and after deaeration at room temperature. It was found that air content has little influence on the cavitation performance, though higher air content distinctly facilitates the cavitation inception. Comparison of the cavitation performance and cavitating structures at different temperatures shows that the intensity of the thermodynamic effect is closely related to the working condition. At a lower cavitation number and flow coefficient (, ), the thermodynamic effect is stronger to suppress the cavitation development inside the inducer, and thus the breakdown point is delayed. But at a larger flow coefficient , higher temperatures show promotion effects on the cavitation breakdown. A semi-empirical theoretical model was employed to quantitatively predict the influence of the thermodynamic effect on the cavitation performance, and the predicted results match well with the experimental results.