The Problem Of Turbulent Boundary Layer In Hydraulic Structure

The research of turbulent boundary layer development on spillway has significance for further understanding high-speed hydraulics and solving energy dissipation problems of discharging structures.Combining with the project of "boundary layer theory and its application in the hydraulic engineering", which was founded by the state key laboratory on high-speed hydraulics, the literatures in the recent 20 years on boundary layer theory and its application in the hydraulic engineering were systematically reviewed, in order to established equations considering gravity and curvature, and discuss its application. The main contents were presented as follows:(1) Considering the influences of gravity and free surface, the momentum integral equation of turbulent boundary layer on steep slopes with limited depth of water, was firstly derived. It was shown by the derivation that Karman's momentum integral equation can be application to flow boundary layer on steep slopes.(2) Based on basic equations of water flow movement on spillway bucket, assuming streamline curvature concentric circles, the formula of water pressure distribution was got. Introducing the concept of laminar swirl-flow layer, the unified expression reflecting the variation of hydrodynamics pressure along normal and tangential direction furthermore was derived, through constructing the adjustment transition streamline and assuming concentric circles. So that the influence of boundary layer on hydrodynamics pressure was considered. The simulating results are in accordant with model test data.(3) The mechanics of turbulent boundary layer evolution on spillway bucket were discussed, and the dimensionless expressions and experiential expressions were obtained. Considering influences of gravity, centrifugal force and curvature, the momentum integral equation and continuity equation were established, then solving them with the Runge-Kutta method. The results were fit well with those by physical model test(4) Application the boundary layer theory to calculate conveyance capacity of sluice weir, the discharge coefficient of the lateral gate, WES weir, round crested weir and broad-crest weir, were obtained.