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为研究竖井溢洪道内部关键部位的压强特性,在维持消能井井径D=7m不变的情况下,分别对消能井井深做T_0=10.29m、T_0=12.29m、T_0=14.29m、T_0=16.29m四种变化方案,并进行模型试验,研究了环形堰面、消能井段、压坡段的时均压强分布、变化规律、脉动压强参数。结果表明:自由堰流下,环形堰面上压强值整体较小,在堰面曲线末端(测点19附近)堰面上产生了负压;消能井底板压强值较大,压强分布随井深的增大而更加均匀;压坡段压强变化随井深的增加没有明显的增减规律;在压坡段顶部测点1处出现负压,但负压值很小,压坡段顶部压强整体值均较小;用测压管测量的时均压强波动数值和脉动压强数值相当;脉动压强的优势频率值小于1Hz,竖井内部水流的脉动压强属于低频范畴。
In order to study the pressure characteristics of key parts in the spillway of shaft, T_0 = 10.29m, T_0 = 12.29m, T_0 = 14.29m, T_0 = 16.29m, and the model test was carried out. The distribution of average pressure at the ring weir, the section of energy dissipation well and the pressure gradient section were studied. The variation law and the fluctuating pressure parameters were studied. The results show that the pressure value on the annular weir is smaller than that on the free weir, and the negative pressure is produced on the weir surface at the end of the curve of the weir (near the measuring point 19). The bottom plate pressure value of the energy dissipating well is larger and the pressure distribution is deeper Increasing and more uniform; pressure gradient section pressure change with the increase of well depth without obvious increase and decrease rule; at the top of the pressure gradient section at 1 point negative pressure, but the negative pressure value is very small, The value of fluctuating pressure was equal to that of pulsating pressure. The dominant frequency of pulsating pressure was less than 1 Hz. The pulsating pressure of shaft internal flow belonged to low frequency range.