Study of Thermodynamic Cavitation Effects in an Inducer

摘要

To investigate the effect of water temperature on the cavitating flow characteristics inside a rotating inducer, aseries of experiments have been conducted based on a model inducer in a newly developed visualization test facilityusing heated water as a working fluid.Apractical image processing method was developed to analyze the visualizationresults quantitatively. The cavitation tests were carried out both before and after deaeration at room temperature. Itwas found that air content has little influence on the cavitation performance, though higher air content distinctlyfacilitates the cavitation inception. Comparison of the cavitation performance and cavitating structures at differenttemperatures shows that the intensity of the thermodynamic effect is closely related to the working condition. At alower cavitation number and flow coefficient (0.8Φ_0, 1.0Φ_0), the thermodynamic effect is stronger to suppress thecavitation development inside the inducer, and thus the breakdown point is delayed. But at a larger flow coefficient(1.1Φ_0), higher temperatures show promotion effects on the cavitation breakdown. A semi-empirical theoreticalmodel was employed to quantitatively predict the influence of the thermodynamic effect on the cavitationperformance, and the predicted results match well with the experimental results.