有坎式台阶溢流坝的数值模拟

Numerical Simulation of the Air-Water Flow on the Steeped Spillway Having Sill

采用RNG k-ε双方程紊流模型,对有坎式台阶溢流坝各体形进行数值模拟,并与传统台阶的水面线、速度场、压强场、消能率等方面进行了比较。研究结果表明:水平台阶上设置坎后的体形对台阶段水面线影响较大,对其他区域水面线影响较小;随着坎高增加,漩涡区域在水平和竖直方向都会增大;传统台阶的负压小于同位置有坎式台阶的负压,随着坎高增加,台阶垂直面的负压减小正压增大。坎的迎水面和坎顶均为正压,且最大压强出现在坎迎水面与水平台阶的交点处;另外,受水平台阶面上坎高的影响,台阶段的消能率略有增加。

In this paper, a type of steeped spillway having sill is studied. By using the RNG k-6 double-equation turbulence model, numerical simulations of the distributions of physical parameters such as water surface profile, velocity field, pressure field and energy dissipation rate in the flow field are performed, and comparisons are made between the traditional stepped spillway and the stepped spillway having sill. The results show that the sill has great effects on the water surface profile on the step, but has little effects on others. With the increase of the sill, the vortex range increases in both horizontal and vertical directions of the step. The negative pressure on the traditional stepped spillway is less than that on the stepped spillway having sill in the same position and with the increase of the sill, the negative pressure decreases and the positive pressure increases on the vertical face of step. There are all positive pressure on the upstream face and top face on the sill, and the maximum positive pressure occurs on the comer of the sill. In addition, the dissipation rate of the steeped spillway having sill is higher than that of traditional stepped spillway.