不同掺气条件下底板水流脉动压强特性研究

Fluctuating pressure characteristics of flow on flume bottom with different aeration conditions

针对水流掺气后对脉动压强特性的改变问题,基于矩形陡槽水工模型试验结果,分析了不同掺气设施及不同通气方式泄槽底板的脉动压力标准差沿程变化规律。分析结果表明,自掺气底板水流脉动压强沿程变化平稳;强迫掺气底板水流脉动压力明显增大,并在水舌冲击区呈单峰规律;单独底坎、单独侧坎和底侧联合坎三种掺气设施中,单独侧坎掺气对底板水流脉动压强影响最小。另外同种掺气设施下,增大流量、增大通气孔面积和采用分散进气方式都会增大泄槽底板的脉动压强。

Aiming at the change of pulsating pressure characteristics after aeration of water.Based on the test results of the rectangular chute hydraulic model,the variation laws of the standard deviation of pulsating pressure on the chute base-slab of different gas-absorbing facilities and different ventilation methods is analyzed.The results show that,in the condition of self aeration,the fluctuation pressure of the bottom plate is smooth along the curve;Forced aeration water flow pulsating pressure increased significantly,especially in the impacted area was a single peak law.Three kinds of aeration facilities:only set the bottom aerator,only set the lateral aerator and the bottom aerator and the lateral aerator set at the same time,the effect of only set the lateral aeration on the pulsation of the bottom plate is the least.For the same bottom aerator,increasing the flow rate,increasing the vent area and decentralized vent holes will increaseing the pressure of the bottom chute.