Modeling and Prototype Testing of Flows over Flip-Bucket Aerators
Modeling and Prototype Testing of Flows over Flip-Bucket Aerators
复制标题
DOI：
10.1061/(asce)hy.1943-7900.0001531
复制
发表时间：
2018-12-01
影响因子：
2.4
通讯作者：
Yang, James
中科院分区：
文献类型：
--
作者：
Teng, Penghua;Yang, James
本文论述了一种独特的溢洪道，它在每个挑坎中加入了一个导流板，目的是使水流掺气，避免射流封闭的低于大气压的空气空腔。在射流破碎和稳定性方面，物理模型和原型得出了相互矛盾的结论。密封曝气器，模型显示完整的空气腔具有负气压，表明曝气的需要。计算流体动力学（CFD）进行，以确定差异的原因。原型观测和计算流体动力学都表明，由于空气夹带，射流破裂;由此产生的空腔气压降微不足道。这种差异是由于模型尺度小，其中空气卷吸的阈值流速不满足，射流破碎的先决条件不存在。为了正确地再现类似的水-空气流动现象，模型应该足够大以满足空气夹带标准。当质疑一个小尺度的模型与空气腔的形成，计算流体动力学模拟应执行检查模型的结果，并作出修正，如果需要的话。(C)2018年美国土木工程师协会。
The paper deals with a unique spillway which incorporates an aerator in each flip bucket with the intention to aerate the flow and avoid subatmospheric air cavities enclosed by the jets. In terms of jet breakup and stability, the physical models and the prototype lead to contradicting conclusions. With sealed aerators, the models exhibit intact air cavities featuring negative air pressure, suggesting the aeration need. Computational fluid dynamics (CFD) is performed to determine the reason for the discrepancy. Both the prototype observations and CFD indicate that the jets break up as a result of air entrainment; the resulting cavity air-pressure drops are insignificantly small. The discrepancy is due to the small model scale, in which the threshold flow velocity for air entrainment is not met and the prerequisite for jet breakup does not exist. To correctly reproduce similar water-air flow phenomena, the model should be large enough to meet the air-entrainment criterion. When questioning a small-scale model with air-cavity formation, CFD simulations should be performed to check the model results and make corrections, if needed. (C) 2018 American Society of Civil Engineers.