Hydraulic response of synchronous closing of main canal gate on Middle Route of South-to-North Water Transfers Project
- Article
- Figures
- Metrics
- Preview PDF
- Reference
- Related
- Cited by
- Materials
Abstract:
The main canal of the Middle Route of the South-to-North Water Transfers Project is separated by gates into series channel pools. In case of emergencies and other situations, the synchronous operation technology of gates is often adopted to rapidly reduce the water flow in a large range. Rapid closing of the gates at both ends of the canal pool will cause continuous oscillation of the water level and flow in the canal pool, and affect the efficiency and effect of the gate feedback control. If the gate is not properly controlled, the water is easy to overflow. It is of great significance to deeply understand the hydraulic response characteristics of synchronous closing of gate and the influence law of related factors for guiding the control of gate scientifically and ensuring the operation safety of the project. Based on Saint-Venant equation group, a one-dimensional unsteady gradually varied flow model for the main canal of the Middle Route of the South-to-North Water Transfers Project was constructed. Taking the canal pool between Diaohe aqueduct gate and Tuanhe aqueduct gate as the research object, the hydraulic response of synchronous closing of the gate was simulated, and the hydraulic response characteristics such as peak water level, time spent to reach the peak water level, frequency and amplitude of hydraulic oscillation before the gate were analyzed. By changing the control mode of gate and the operating conditions of canal, the influences of gate closing duration, gate closing amplitude, operating water level, water delivery flow and canal roughness on hydraulic response characteristics were analyzed and summarized.Simulation results showed that the rise process of hydraulic oscillation was fast, but the fall process was slow. The amplitude of the wave was approximately logarithmic function attenuation with time, and the time interval of the adjacent wave peaks and valleys gradually tended to be consistent. The peak height of backwater and amplitude of hydraulic oscillation in front of the gate can be reduced approximately linearly by slowly closing and decreasing closing amplitude. The decreasing amplitude was a zonal distribution function with gate closing time. With the increase of operating water level, the peak value of rising water in front of the gate decreased linearly. The time taken to reach the peak and the amplitude of hydraulic oscillation had no obvious change, but the oscillation frequency increased slightly. With the increase of the water flow, the peak value of backwater in front of the gate increased linearly. The time taken to reach the peak had no obvious change in the frequency of hydraulic oscillation, but the amplitude decreased obviously and the attenuation became faster. With the increase of roughness, the peak of backwater before the gate increased linearly, the time taken to reach the peak, and the frequency and amplitude of hydraulic oscillation had no obvious change. The hydraulic response is determined by the difference of the movement characteristics between the increasing wave and the decreasing wave, as well as the difference while traveling downstream and upstream, and the energy dissipation along the travel. The amplitude of hydraulic oscillation is sensitive to the closing speed and closing amplitude of the gate. The value deviation of roughness can be ignored when estimating peak backwater before the gate.
Keywords:
Project Supported:
Clc Number:
Mobile website
® 2024 All Rights Reserved
冀公网安备13010502002656号
冀公网安备13010502002656号