Experimental and field study on dissipation coefficient of supersaturated total dissolved gas
来源期刊：中南大学学报(英文版)2014年第5期
论文作者：FENG Jing-jie(冯镜洁) LI Ran(李然) MA Qian(马倩) WANG Le-le(王乐乐)
文章页码：1995 - 2003
Key words：total dissolved gas; dissipation coefficient; longitudinal model; hydrodynamics
Abstract: The elevated supersaturation of total dissolved gas (TDG) downstream of a high-dam spill has deleterious effects on fish in a large range. A one-dimensional (1-D) longitudinal model is optimal for the prediction of supersaturated TDG dissipation over a long distance. The key issue of the model is to determine the dissipation coefficient accurately. In agreement with field observations and experiment data, dimensional analysis and regression were performed to propose a formula for estimating the dissipation coefficient of supersaturated TDG in various rivers and reservoirs, and it involves the effects of the turbulence intensity, the hydro-pressure and the solid-liquid interface. The friction velocity, water depth, hydraulic radius and Froude number are independent variables in the formula which are easy to determine in practical applications. The 1-D longitudinal model is implemented to calculate the dissipation of TDG in a reach of the Jinsha River. Good agreement is found between the calculated results and field data for both the dissipation coefficient and the dissipation process.
FENG Jing-jie(冯镜洁), LI Ran(李然), MA Qian(马倩), WANG Le-le(王乐乐)
(State Key Laboratory of Hydraulics and Mountain River Engineering (Sichuan University), Chengdu 610065, China)
Abstract:The elevated supersaturation of total dissolved gas (TDG) downstream of a high-dam spill has deleterious effects on fish in a large range. A one-dimensional (1-D) longitudinal model is optimal for the prediction of supersaturated TDG dissipation over a long distance. The key issue of the model is to determine the dissipation coefficient accurately. In agreement with field observations and experiment data, dimensional analysis and regression were performed to propose a formula for estimating the dissipation coefficient of supersaturated TDG in various rivers and reservoirs, and it involves the effects of the turbulence intensity, the hydro-pressure and the solid-liquid interface. The friction velocity, water depth, hydraulic radius and Froude number are independent variables in the formula which are easy to determine in practical applications. The 1-D longitudinal model is implemented to calculate the dissipation of TDG in a reach of the Jinsha River. Good agreement is found between the calculated results and field data for both the dissipation coefficient and the dissipation process.
Key words:total dissolved gas; dissipation coefficient; longitudinal model; hydrodynamics
