Minimum pressure calculation of vortex for stilling basin with step-down floor

Xia Quing-fu, China Institute of Water Resources and Hydropower Research
Liu Zhi-ping, China Institute of Water Resources and Hydropower Research
Guo Xin-lei, China Institute of Water Resources and Hydropower Research

Description

The horizontal vortex flow in the stilling basin with step-down floor is the special problem of hydraulics. In the horizontal vortex, the vortex flow streamline is assumed to be elliptical. According to the hydrodynamics of continuous and motion differential equations, the vortex pressure, vorticity, and other hydraulic characteristics are deduced in the vortex. The concept of velocity attenuation coefficient is proposed in this work, and a movement connection condition is established. The relationship between the minimum pressure of the vortex flow and the downstream water depth is studied, and a formula to calculate the minimum pressure is given. Compared with the numerical simulation results, the proposed formula enhances the accuracy of guiding the actual project. The minimum pressure of the vortex in the Xiangjiaba Hydropower Station and the Guandi Hydropower Station is calculated using the proposed formula.

 
Jun 29th, 4:00 PM Jun 29th, 6:00 PM

Minimum pressure calculation of vortex for stilling basin with step-down floor

Portland, OR

The horizontal vortex flow in the stilling basin with step-down floor is the special problem of hydraulics. In the horizontal vortex, the vortex flow streamline is assumed to be elliptical. According to the hydrodynamics of continuous and motion differential equations, the vortex pressure, vorticity, and other hydraulic characteristics are deduced in the vortex. The concept of velocity attenuation coefficient is proposed in this work, and a movement connection condition is established. The relationship between the minimum pressure of the vortex flow and the downstream water depth is studied, and a formula to calculate the minimum pressure is given. Compared with the numerical simulation results, the proposed formula enhances the accuracy of guiding the actual project. The minimum pressure of the vortex in the Xiangjiaba Hydropower Station and the Guandi Hydropower Station is calculated using the proposed formula.