Numerical Simulation on Hydraulic Characteristics of Underflow for Falling-Sill Bottom-Flow Dissipation

Falling-sill bottom-flow dissipation is an important energy dissipater way, which has two fluent characteristics, spatial 3D hydraulic jump and submerge jet. But the turbulent motion is strong with a flow pattern of complex level. It is hard to detail the hydraulic characteristics and strength being inside of the plunge pool using physical experiments. However, numerical simulation can match the deficiency of physical model, which has the access to detail flow field hydraulic characteristics and provide a strong scientific basis on analyzing the hydrodynamic and hydraulic characteristics of plunge pool. In this paper, XJB project is taken for example, gas-liquid two-phase flow tracking the simulation free surface of VOF model was used. The RNG κ_e turbulent motion model is adequate to simulate the 3D flow field in plunge pool. The result shows that the consequence of numerical simulation and physic test match well, which can reflect the plunge pool hydraulic characteristics and dissipation process accurately. The distribution of flow speed inside the plunge pool locates the position of main flow and reflects the velocity decay along the way and reflux flow vortex .