Evaluation of cavitation in injector nozzle and correlation with liquid atomization

Present paper describes the correlation between occurrence of cavitation inside injector nozzle and progress of atomization in discharged liquid jet flow. A transparent two-dimensional shape nozzle was designed and it was used for flow visualization. The visualized images both of cavitation and atomization were obtained simultaneously. The cavitation was evaluated by applying image analysis. The quantitative analysis on length, thickness and their fluctuations of cavitation was made, and the correlation with atomization was examined. The authors proposed an evaluation method of atomization in the previous study, and it was combined with evaluation method of cavitation developed in this study. It is found that the change of cavitation and progress of atomization are synchronized, and that a strong correlation between them exists. The best performance of atomization may be obtained by controlling the cavitation inside nozzle, and obtained aspects with this study will be utilized for the design of fuel injection nozzle of internal combustion engines.