Numerical Simulation And Experimental Study On Hydraulic Characteristics Of Spillway Bend

Based on computational software Fluent, the three-dimensional flow in spillway bend and energy dissipation of Heihushan reservoir in Qingzhou city had been numerical simulated by the volume of fluid (VOF) two-phase flow model as the iteration of calculation and compared standard k-ε equation turbulent model with Realizable k-ε turbulence model. The result was to choose out the optimization of the energy dissipation of the spillway bend according to the reliability of numerical simulation results given by physical model. The main content and achievements include that:(1) Taking Heihushan reservoir bend as an example and adopting physical model test to study the hydraulic characteristics improvement in the spillway chute on account of setting guide wall and the impact of energy dissipation method on the downstream channel erosion. The hydraulic parameter such as the water surface curve at left and right bank of chute and the velocity in section was measured in different water drainage conditions to do the research about the influence of different working conditions on the downstream energy dissipation section.(2) The three-dimensional numerical simulations on the spillway chute and energy dissipation section has been done. In the process of calculation, standard k-ε equation turbulent model is compared with Realizable k-ε turbulence model. VOF method and unstructured grid are used separately to make tracks for free surface and partition boundary geometrical. The secondary flow of reflexion and scour flow and some major parameters like water surface, velocity of length in spillway chute are calculated. Through compared with the parameters obtained from physical model test, Realizable k-ε turbulence model is proved to be more suitable for the calculation of parameters in chute.(3) On the basis of above, the design of ski-jump energy dissipation is optimized, In the energy dissipation of flip bucket view, lateral displacement current is smaller when bucket angle is 22°than the original 20°. Further more, the distribution of jet trajectory length in landscape is uniform and symmetric. The maximum jet trajectory length is still in the central location. Otherwise, the increase of length makes energy dissipation efficiency promote obviously. Uniform deflecting flow can avoid undermining to the local area of scouring pit and rock mass near the base of flip bucket and provide guarantee for the safety of scouring pit, flip bucket and surrounding buildings. At the same time, flow velocity in flip bucket decreases, which leads transverse shear force to decrease and reduces the damage to the bucket lip.