Numerical Simulation Of Hydrodynamic Characteristic In The Middle Bank Stilling Pool

With the development of turbulence theory and computer technology,numerical simulation is used more and more comprehensive in hydraulic project and methods in the study of hydraulics.The paper used standard k ?εturbulence model,sets up 3D numerical model and simulates the whole process of gate discharge:(1) Based on the Banzhuyuan Hydroelectric Station ,at the pond set middle bank,coming up with the pond of middle bank,set up the 3D model of the pond of the middle bank,the profile vector diagram of the velocity,the contour map of surface current,The profile distribution map of turbulent energy and The profile distribution map of turbulent energy dissipation rate are obtained through computing,by analysis flow pattern in the pond of middle bank and compare the data with the experimental data;(2)The paper analyses and compares the factor effect on the flow in the pond of middle bank by the numerical simulating.The analysis shows the flow structures in the pond of middle bank are not only related with the incoming flow,the location of the middle bank,the height of middle bank,the height of tail bank and the length of apron extension and so on.The elementary flow structure is a mixed structure of the main jet section and the swirl.The boundary section is a strong turbulent cut section.The main jet mainly dissipates the energy in this section.The numerical simulation validates that the flow tongue of jet is helpful to dissipate the energy of water.It also proves the effect of dissipating energy is better;(3) In the paper,the energy dissipation characteristics of the pond are studied and analyzed.The analysis showed:The relations between the energy dissipation rate and the top weir flow is little relevance;When middle bank is three quarters higher than overflow dam,the energy dissipation ratio of middle bank more better;The location of middle bank two thirds in the pond,the energy dissipation effectiveness is best;Compare with no middle bank,when step up the bank the efficiency of energy dissipation obvious improves 2~3 times,come to 62 percent,the efficiency of the middle bank increase to 75 percent,reduce to scour of downstream.