Bottom and side-wall aeration performance of an offset aerator in a flood discharge chute

IF 16.4 1区化学 Q1 CHEMISTRY, MULTIDISCIPLINARY

Accounts of Chemical Research Pub Date : 2022-06-20 DOI:10.1680/jwama.21.00053

Xuechun Liu, Ruidi Bai, Shan-jun Liu, Zhong Tian

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引用次数: 1

Abstract

Building a chute aerator is an efficient measure to protect the chute bottom from cavitation damage in large flood-discharging hydraulic structures, but it sometimes fails to provide sufficient protection to the sidewalls. In this paper, basic air-water flow properties are investigated for discharge flows over an offset chute aerator model, with particular focus on the near-bottom and near-wall regions, for a range of discharge velocities over the offset brink 3.58 m/s < V < 8.02 m/s, Froude numbers 4.8 < Fr < 12.0, and Reynolds numbers 8.0×104 < Re < 9.2×104. Observations indicate little transverse variations in air-water flow properties except near the jet impact perimeter. The bottom air concentration and bubble frequency decrease at different rates downstream the impact point, and the influence of the Reynolds number on the bubble size and density should not be ignored. The shape of the clear-water core between the upper and lower aeration layers is identified with the aid of high-speed imaging and air concentration calibration against the wall. A formula is proposed to predict the narrowing of the jet core until its ending position.

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泄洪槽中偏置式曝气器的底部和侧壁曝气性能

在大型泄洪水工建筑物中，设置溜槽曝气器是保护溜槽底部不受空化破坏的有效措施，但有时对侧壁的保护不够。本文研究了偏置溜槽增氧机模型的基本空气-水流动特性，特别关注近底部和近壁面区域，偏置边缘上的排放速度范围为3.58 m/s < V < 8.02 m/s，弗劳德数4.8 < Fr < 12.0，雷诺数8.0×104 < Re < 9.2×104。观测表明，除了在射流撞击周界附近，空气-水流动特性的横向变化很小。在撞击点下游，底部空气浓度和气泡频率以不同速率下降，雷诺数对气泡大小和密度的影响不容忽视。借助高速成像和壁面空气浓度标定，确定了上下曝气层之间的清水岩心形状。提出了一种预测射流核心缩窄直至其结束位置的公式。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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来源期刊

Accounts of Chemical Research 化学-化学综合

CiteScore

31.40

自引率

1.10%

发文量

312

审稿时长

2 months

期刊介绍： Accounts of Chemical Research presents short, concise and critical articles offering easy-to-read overviews of basic research and applications in all areas of chemistry and biochemistry. These short reviews focus on research from the author’s own laboratory and are designed to teach the reader about a research project. In addition, Accounts of Chemical Research publishes commentaries that give an informed opinion on a current research problem. Special Issues online are devoted to a single topic of unusual activity and significance. Accounts of Chemical Research replaces the traditional article abstract with an article "Conspectus." These entries synopsize the research affording the reader a closer look at the content and significance of an article. Through this provision of a more detailed description of the article contents, the Conspectus enhances the article's discoverability by search engines and the exposure for the research.