Experimental Study On Gas Migration And Diffusion In The Flow Structure Of The Underflow Energy Dissipator

Many of China's dam project is more than 70m high dam,ultra high dam,its flood discharge,flood discharge power,aeration and energy dissipation and other engineering characteristics compared to the low dam is very different,and in recent years water conservancy and hydropower engineering using a new type of energy dissipation of working gas caused by super saturation and cavitation problems are more prominent.More importantly,the environmental impact assessment of the built and under construction water conservancy and hydropower projects in China has not yet been carried out.Underflow energy dissipation is a traditional energy dissipation method,and the gas migration and diffusion characteristics under the water flow structure can be studied,which can provide important basis for the gas migration,diffusion and release mechanism and the mechanism of gas movement under different water flow structures,in order to reduce the concentration of the total dissolved water in the downstream water,thus protecting the river water ecology and water environment to lay the theoretical basis.In bottom-flow energy dissipation,high-speed flow into the power of the pool,and the power of the pool there is a strong turbulent flow of water,bubbles continue to gather together,split and rise phenomenon,water and bubble between the momentum of the exchange,the bubble contributed most of the gas transmission quality is accompanied by a large amount of mechanical energy loss.A large amount of air blending,so that the depth of the basin to increase the water,but also cause additional turbulent diffusion of water flow,the flow of the flow of the pool and the pressure distribution has a certain impact.Therefore,the study of aeration flow is of great significance to the optimization design of the bottom-flow energy dissipated body.This paper is based on the National Natural Science Foundation of China,which is based on the research on the mechanism of gas migration and diffusion in different water structures under high water discharge and flood discharge.(Item No.51669007).By means of the combination of hydraulic model test and theoretical analysis,the flow rate,the mean pressure and the mixed air concentration of the water flow structure area were measured in different into the pool energy,candy height and air ratio.Using a single variable method,analysis the effect of different hydraulic conditions on the distribution of flow rate and the mean pressure,the distribution of the mixed air concentration and the law of the gas migration and diffusion.