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Bubble size characteristics in the wake of ventilated hydrofoils with two aeration configurations
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 Title & Authors
Bubble size characteristics in the wake of ventilated hydrofoils with two aeration configurations
Karn, Ashish; Ellis, Christopher R; Milliren, Christopher; Hong, Jiarong; Scott, David; Arndt, Roger EA; Gulliver, John S;
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 Abstract
Aerating hydroturbines have recently been proposed as an effective way to mitigate the problem of low dissolved oxygen in the discharge of hydroelectric power plants. The design of such a hydroturbine requires a precise understanding of the dependence of the generated bubble size distribution upon the operating conditions (viz. liquid velocity, air ventilation rate, hydrofoil configuration, etc.) and the consequent rise in dissolved oxygen in the downstream water. The purpose of the current research is to investigate the effect of location of air injection on the resulting bubble size distribution, thus leading to a quantitative analysis of aeration statistics and capabilities for two turbine blade hydrofoil designs. The two blade designs differed in their location of air injection. Extensive sets of experiments were conducted by varying the liquid velocity, aeration rate and the hydrofoil angle of attack, to characterize the resulting bubble size distribution. Using a shadow imaging technique to capture the bubble images in the wake and an in-house developed image analysis algorithm, it was found that the hydrofoil with leading edge ventilation produced smaller size bubbles as compared to the hydrofoil being ventilated at the trailing edge.
 Keywords
Ventilated hydrofoil;Hydroturbine aeration;Shadow Image Velocimetry;Bubble size distribution;Auto-venting turbines;
 Language
English
 Cited by
1.
Gas entrainment behaviors in the formation and collapse of a ventilated supercavity, Experimental Thermal and Fluid Science, 2016, 79, 294  crossref(new windwow)
2.
Gas transfer in a bubbly wake flow, IOP Conference Series: Earth and Environmental Science, 2016, 35, 012020  crossref(new windwow)
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