Author:
Bai Ruidi,Liu Chang,Feng Bingyang,Liu Shanjun,Zhang Faxing
Abstract
Chute aerators introduce a large air discharge through air supply ducts to prevent cavitation erosion on spillways. There is not much information on the microcosmic air bubble characteristics near the chute bottom. This study was focused on examining the bottom air-water flow properties by performing a series of model tests that eliminated the upper aeration and illustrated the potential for bubble variation processes on the chute bottom. In comparison with the strong air detrainment in the impact zone, the bottom air bubble frequency decreased slightly. Observations showed that range of probability of the bubble chord length tended to decrease sharply in the impact zone and by a lesser extent in the equilibrium zone. A distinct mechanism to control the bubble size distribution, depending on bubble diameter, was proposed. For bubbles larger than about 1–2 mm, the bubble size distribution followed a—5/3 power-law scaling with diameter. Using the relationship between the local dissipation rate and bubble size, the bottom dissipation rate was found to increase along the chute bottom, and the corresponding Hinze scale showed a good agreement with the observations.
Funder
National Natural Science Foundation of China
Subject
Water Science and Technology,Aquatic Science,Geography, Planning and Development,Biochemistry
Reference31 articles.
1. Scale effects in modeling air demand by a ramp slot;Pan;Scale Eff. Model. Hydraul. Struct.,1984
2. Air Entrainment by Spillway Aerators
3. Air bubble entrainment in turbulent water jets discharging into the atmosphere;Chanson;Aust. Civ. Eng. Trans.,1996
4. Air transport in chute flows
5. Development of Air Concentration on Chute Spillways
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