Numerical Simulatioan On Energy Dissipation Jointed Effects Of Tod Spillway And Bottom Outlet Flood

Energy dissipation,as a basic form of energy dissipation,has been widely used in water conservancy projects at home and abroad.Layout and design of the underflow discharge facilities had a direct impact on the flow pattern and energy dissipation efficiency of the energy dissipation basin and were closely related to the local scour of downstream riverbed.Therefore,studying on size and layout of the optimization of discharge structures has a very important meaning to ensure that the dam can discharge flood safely.Physical experiments in a large-scale hydropower station surface and bottom joint flood discharge facilities based,used standard turbulence model and VOF free sur,face capture technology,three dimensional flow field of the combined flood which in 2000-years check flood standard,500-year return period flood design standards,design standards in 50-years and in 10-years the design standard was numerical simulated,we obtained the flow velocity,water line and pressure hydraulic characteristics of the surface orifice spillway,bottom outlet and the pond.And then the comparison between simulated and experimental data is made.Results show that:the original design of the stilling pool water fluctuation,flow disorder,pool water secondary sag and mainstream dive riverbed,lateral diffusion is not sufficient.The corresponding physical model,which occurs serious erosion in the downstream.Erosion is the most serious on the right bank and behind the left guide wall of surface hole,is just on,the right bank of the mainstream posted shore and left back pressure area.Furtheramore,the optimization scheme was simulated in 500-year design flood standards,50-years design standards,10-years and 2-years design standards thrrough improved the shape of the plunge pool with the methods of retaining the construction diversion wall between low porosity and surface hole stilling pools and so on.the flow regime of stilling basin was significantly improved and the pool water secondary drop decreasesed,dive was weakened,a pool level of the mainstream diffusion more fully,lateral extrusion could be suppressed sufficiently.Accordingly,the scope and depth of the riverbed erosion are greatly reduced,especially on the right bank side corresponds to the original proposal prepared hole area almost no erosion occurs.Research shows that the the discharge structure flow can be simulated well,using the method of mathematical model,and the detailed flow field information can be obtained.Through the analysis of the energy dissipation pool flow,velocity,pressure and water surface profile and other characteristics of the flow field,in the simulation of local scour is still not mature,establishing the relationship between discharge construction logistics field of hydraulic characteristics and downstream scouring.Considering the characteristics of flow field and downstream scour synthetically,the rationality of design parameters of energy dissipater can be evaluated and the shape and layout of discharge structures can be optimized.