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http://dx.doi.org/10.5407/jksv.2019.17.1.060

Flow visualizations and analysis on characteristics of bubbly flows exhausted from a venturi-type bubble generator with an air vent  

Bae, Hyunwoo (Graduate School, Department of Mechanical Engineering, Seoul National University of Science and Technology)
Lee, Seungmin (Graduate School, Department of Mechanical Engineering, Seoul National University of Science and Technology)
Song, Moonsoo (Department of Mechanical and Automotive Engineering, Seoul National University of Science and Technology)
Sung, Jaeyong (Department of Mechanical and Automotive Engineering, Seoul National University of Science and Technology)
Publication Information
Journal of the Korean Society of Visualization / v.17, no.1, 2019 , pp. 60-68 More about this Journal
Abstract
Flow visualizations have been carried out to analyze the characteristics of bubby flows exhausted from a venturi-type bubble generator with an air vent. For various design parameters and operating conditions of the bubble generator, the images of bubbly flows was recorded using a high-speed camera and a microscope. Then the amount and size distribution of bubble was evaluated by an image processing technique. The results show that for increasing the amount of bubble, it is more effective to reduce the venturi throat than to enlarge the air vent diameter. If the water flow rate increases, the bubble generation rate increases but reaches a status of saturation, whose condition depends on Reynolds number at a given air vent diameter. The bubble size increases as the diameter of venturi throat decreases and Reynolds number increases. However, the air vent diameter is not a significant factor on bubble size.
Keywords
Bubble generator; Venturi tube; Bubble size distribution; Area fraction; Sauter mean diameter;
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Times Cited By KSCI : 2  (Citation Analysis)
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