IAHR, founded in 1935, is a worldwide independent member-based organisation of engineers and water specialists working in fields related to the hydro-environmental sciences and their practical application. Activities range from river and maritime hydraulics to water resources development and eco-hydraulics, through to ice engineering, hydroinformatics, and hydraulic machinery.
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You are here : eLibrary : IAHR World Congress Proceedings : 34th Congress - Brisbane (2011) : THEME 4: Responding to Shifting Water Resources : Application of annular aerators in tunnels
Application of annular aerators in tunnels
Author : M.J.Ostadmirza1, A.R.Zarrati1, R.Roshan2 and Kh.Safavi2
Aerators are constructed in high speed flows to prevent cavitation attack. Although horseshoe or circular tunnel sections can be converted to rectangular shape to use aerators similar to chute spillways, such a solution needs expensive subsequent concrete operation. Alternatively, annular aerators could be constructed which fit well with the tunnel section. There is however no information for design of annular aerators available in the literature. In the present study different annular aerator sizes were tested in a large physical model of a bottom outlet 40 m long and 0.38 m in diameter. Flow discahrge and depth as well as air concentration near the tunnel invert were measured to compare different aerators' performance. Each aerator was tested at different flow discharges and upstream gate openings. Experiments showed that the aerator shape should follow the tunnel section. The effect of aerator geometry and flow condition on air concentration reduction in deaeration zone was also found in these experiments. Based on experimental data an empirical equation was also developed for the effective length of annular aerators.
File Size : 466,298 bytes
File Type : Adobe Acrobat Document
Chapter : IAHR World Congress Proceedings
Category : 34th Congress - Brisbane (2011)
Article : THEME 4: Responding to Shifting Water Resources
Date Published : 01/07/2011
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