3-D Numerical Simulation Of Scouring Process In Downstream Of Juting Hydropower Station

With the reduction of high-head hydropower resources, the development of low-headpower station will become a major trend in the development of hydropower resources.Low-head hydropower plants with a low head, big flow and small Froude number, are built inthick layer with gravel covered. So dam downstream erosion damage occurs very commonand some apron is also damage, especially in cross-strait slope the erosion is more serious. Iteven leads to damage to the building and directly affect the safe operation of the sluice.Therefore correct prediction and forecast about the shape, depth and other internal flow fieldinformation of the scour at downstream of discharge structures is of great significance for thesecurity of discharge structures.With Juting hydropower station for the study, the three-dimensional numericalsimulation of flow field and the discharge process water erosion process were simulated. Theresults obtained can be summarized as follows.(1) Through the establishment of a mathematical model，flow field of Juting hydropowerstation was simulated. A reasonable flow field numerical simulation can be obtained andcomposition the flow field information of hydraulic model and the results of computingverified the accuracy of the mathematical model.(2)The shear stress of bed as a starter criterion was obtained using ANSYS FLUENTUDF program wrote with C language to control the movement of the grid of the bottomboundary at erosion area. The calculation proceeding information and shear stress of movingbed were obtained. With the dynamic mesh model to achieve the reconstruction of the grid,the computing area grid was updated at each time step. The numerical simulation results ofthe maximum scour depth and shape of the river bed downstream of coincided well withphysical model test values.(3)The wall shear stress gradually decreases with erosion time increasing in the erosionprocess. The deepest point in the scour hole section has the minimum wall shear stress valuesin space distribution. The wall shear stress decreases upstream of the deepest point. The wallshear stress increases downstream of the deepest point.