Limited by measuring means, the conventional physical model test almost couldn't comprehensively study the variation of hydraulics parameters in the deep tail water stilling basin. Based on the renormalization group (RNG) k-ε turbulence model and the volume of fluid (VOF) method, the flow field variation in the deep tailwater stilling basin of the flat gate pier program and incomplete flaring gate pier program were respectively studied, and the energy dissipation mechanism of incomplete flaring gate pier was revealed. Research results show that restricted by the longitudinal overflow weir length and the deep tailwater in the stilling basin, the submerged hydraulic jump approaches weir crest in the flat gate pier program, leading to the insufficient energy dissipation turbulence in the stilling basin and strong secondary hydraulic jump outside the stilling basin. The incomplete flaring gate pier program restricts the overflow weir chamber width to result to the longitudinally stretched water jet, and the asymmetric water flow is utilized in the adjacent chamber to enhance the lateral flow velocity gradient and the water level drop. The large vertical axis rolling from the bottom to the surface is created in the upstream region of stilling basin by the intensified lateral diffusion and intersection, which significantly enhances energy dissipation in the stilling basin, inducing the flow rate of outlet water and achieving well energy dissipation effect. © 2017, Editorial Board of Journal of Huazhong University of Science and Technology. All right reserved.
