Microanalysis of supersaturated gas release based on wall-attached bubbles  

作　　者：Lu Lin Ran Li Jing-jie Feng Ying-han Huang Xiao-dong Yong Yang-ming Ou You-quan Yuan 

机构地区：[1]State Key Laboratory of Hydraulics and Mountain River Engineering,Sichuan University,Chengdu 610065,China [2]Power China Zhongnan Engineering Corporation Limited,Changsha 410014,China [3]Sichuan Qingyuan Engineering Consulting Co.,Ltd.,Chengdu 610072,China [4]College of Architecture and Civil Engineering,Chengdu University,Chengdu 610106,China

出　　处：《Water Science and Engineering》2021年第1期80-86,共7页水科学与水工程（英文版）

基　　金：This work was supported by the National Key Research and Development Program of China(Grant No.2016YFC0401707);the National Natural Science Foundation of China(Grant No.51879173).

摘　　要：Supersaturation of dissolved gases in natural water,due to spillage from high dams and other factors,may cause fish mortality.In previous experiments,the dissipation coefficient has been used to denote the degassing process of total dissolved gas(TDG)saturation.These experiments mainly analyzed supersaturated TDG dissipation from a macroscopic view.To precisely clarify the mechanism of supersaturated TDG release,this study investigated bubble adsorption at a wall surface from a microscopic view.The experiment was conducted in a Plexiglas-wall container filled with supersaturated TDG water.A model that calculates the adsorption flux of supersaturated TDG by a solid wall,and helps describe construction for a contact angle at a three-phase intersection,was developed according to Young's equation.This model was used to investigate the formation process of bubbles adsorbed on a solid polymethyl methacrylate(PMMA)surface in supersaturated TDG water.The adsorption effect of a solid wall on TDG release was analyzed based on the experimental data.The modeling results were compared with observations under different wall area conditions,and it was found that TDG release tended to increase with wall area.This study helps improve our understanding of the mechanisms of supersaturated TDG release and provides an important theoretical method for accurate calculation of the release process.The adsorption flux model of the solid wall provides mitigation measures to combat the adverse effects of TDG supersaturation,which will be beneficial to the protection of aquatic organisms in hydropower-regulated rivers.

关 键 词：SUPERSATURATION Total dissolved gas Wall-attached bubbles Release Calculation model 

分 类 号：TV131[水利工程—水力学及河流动力学]