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为研究输水系统中堰井段水面的波动现象,采用Realizableκ-ε紊流模型耦合VOF法对分段低压输水系统进行二维数值模拟,分析了堰后水深对水面波动规律的影响,探讨了在外加扰动作用下水面波动的规律。结果表明,堰后存在高、低两个水位区间,堰后水位处于这两个区间时,水面将会以某一主要频率稳定持续地波动;当堰后水位处于这两个区间之外时,水面波动变得无规律或只有微弱的波动。外加扰动对水面波动会造成一定影响,当外加扰动频率与水面波动固有频率一致时,即使外加扰动强度很小也会引起水力共振,水面波动幅度大大增加;外加扰动频率与固有频率相差较大时,水面波幅在某些特定时刻达到最大,然后减小到最小值,再增大到最大值,波动幅值的变化呈周期性,并推导出了相应的周期公式,为相关研究提供了参考。
In order to study the fluctuating phenomenon of water surface in weir section of water conveyance system, two-dimensional numerical simulation of subdivision low pressure water delivery system is carried out by Realizable κ-turbulence model coupled with VOF method, and the influence of water depth after weir on water surface fluctuation is analyzed. The law of water surface fluctuation under the action of external disturbance. The results show that there are two high and low water level intervals after the weir. When the water level behind the weir is in these two intervals, the water surface will fluctuate steadily with a certain main frequency. When the water level behind the weir is outside these two intervals, Fluctuations in the water become irregular or have only slight fluctuations. When the external disturbance frequency is the same as the natural frequency of the water surface fluctuation, even if the external disturbance intensity is small, it will cause hydraulic resonance and the water surface fluctuation amplitude greatly increases. When the external disturbance frequency and the natural frequency differ greatly , The amplitude of the water surface reaches the maximum at some specific moment, then decreases to the minimum and then increases to the maximum. The variation of the fluctuation amplitude is periodic, and the corresponding periodic formula is derived, which provides a reference for the related research.