多孔弹性膜对调压室涌波的削减作用

The effect of porous elastic membrane on reducing fluctuations in surge tank

为减少调压室工程量并保证引水系统安全高效运行,提出了调压室内部布置多孔弹性膜方案,以削减调压室涌波幅度并使波动快速衰减。采用"U"型管水柱振荡模型进行物理试验对方案进行了验证,得到了涌波削减效果与多孔弹性膜的开孔面积成反比,与布置层数成正比的规律。通过CFD数值仿真计算对调压室内部的流场特性进行分析,以阐释其消能效果的原理。研究表明,布置多孔弹性膜扰动调压室内部的流场,产生涡带、旋滚和绕流,增大水体波动时的水头损失,使得调压室内水体能量得以耗散,达到快速削减调压室涌波的效果。数值仿真计算结果和物理模型试验具有较好的一致性。对于增加引用流量增效扩容的水电站,设置多孔弹性膜可作为不重建引水发电系统的改造方案。

In order to reduce the work amount of engineering and to facilitate the safe and efficient operation of the water diversion system,a scheme of a porous elastic membrane inside the surge tank was proposed.This measure enabled to reduce the surge amplitude and rapidly damping water level fluctuations.The "U"-shaped water column oscillation model was used for the physical model test.The results showed that the surge reduction effect was inversely proportional to the open area of the porous elastic membrane and was proportional to the number of layers of porous elastic membrane.In order to explain the mechanism of energy dissipation effect,CFD numerical simulations were carried out to analyze the flow field characteristics of the surge tank.The study showed that the porous elastic membrane was arranged to disturb the flow field inside the surge tank,generating vortex,rolling and flow,and increasing the head loss when the water fluctuated.Under the combined action,the energy of the water in the surge tank could be dissipated,and the surge amplitude in the surge tank could be quickly damped.The results obtained by numerical simulation had good agreement compared to the physical model.A porous elastic membrane placed inside the surge tank could be an option instead of the reconstruction of the water conveyance system for the hydropower station in which the installed capacity could be increased by adding discharge.