Study Of Hydraulic Characteristics And Energy Dissipation Of Water Around The Fixed-Cone Valve In Pipelines

The numerical simulation was used to the flow near the Fixed-cone valve,in the hood and the downstream pipeline in the water release for the Bakun Hydropower by applying 2-D and 3-D RNGκ-εturbulence model。The discrete equation was solved by PISO method and the free surface was computed with VOF method.The 2-D numerical research gives the whole process of the water movement which includes jet,energy dissipation near the Fixed-cone valve,in the hood and in the downstream Pipeline, and gives the velocity vector,the pressure distribution around the Fixed-cone valve,in the hood and in the downstream pipeline.According to the ration of air flow to water the valve cone shape was optimizedThe 3-D numerical research gives the flow process when the valve is full operation in four different water level.It mainly gives the vertical and longitudinal distribution of pressure,the ration of air flow to water and the velocity vector in high water level condition.Based on the analysis of the distribution of pressure,the law has been determined around the Fixed-cone valve and downstream pipeline.According to the ration of air flow to water the free surface and water law was determined in the downstream pipeline.The distribution of velocity was analyzed and calculated in the all region,the energy dissipation near the Fixed-cone valve was researched and analyzed on the base of calculation velocity.Comparing the simulating results with the experimental ones,the result showed the proposed model is reliable.So the Fixed-cone valves and Hood can are used to regulate flow under medium to high head conditions because of their ability to safely and efficiently pass the flow.The research provides an reference for the designing and engineering,and has a very important signification.