Details

Autor(en) / Beteiligte

• Wei, Wang-ru
• Xu, Wei-lin
• Deng, Jun
• Tian, Zhong
• Zhang, Fa-xing

Titel

Analysis on Link Between the Macroscopic and Microscopic Air–Water Properties in Self-Aerated Flows

Ist Teil von

• China ocean engineering, 2018-10, Vol.32 (5), p.614-623

Ort / Verlag

Nanjing: Chinese Ocean Engineering Society

Erscheinungsjahr

2018

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• Self-aeration in high-speed free surface flows occurs commonly and is of interest to ocean engineering, hydraulic engineering, and environmental engineering. For two-phase air–water flows, macroscopic air–water flow properties develop gradually, accompanied by the change of microscopic air–water structures. In this article, representational experimental studies on macroscopic and microscopic characteristics of self-aerated open-channel flows are summarized and compared. The isolated effect of the flow Reynolds number and air quantity on the differences in air count rate and chord size are analyzed and discussed. The results show that the characterized flow depth y 50 , affected by the turbulence transfer, is a specific criterion to distinguish the interior air–water structure development. Two distinct linear trends of self-aeration are found, depending on the y 50 / y 90 variation with a breaking point at C mean = 0.50. The air count rate and size scale in self-aerated flows are affected by the air quantity of self-aerated flows, even with identical flow Reynolds numbers. Thus, a specific parameter is proposed to assess the air–water structures and a series of self-similarity relationships in self-aeration properties are obtained. The link between macroscopic and microscopic air–water properties results in significant scale effect on air–water structures in self-aerated flows.