基于消能井井深变化下的竖井溢洪道压强试验研究  

Experimental study on pressure of shaft spillway with different depth of stilling well

作　　者：陈小威[1] 张宗孝[1] 刘冲[1] 白欣[1] 

机构地区：[1]西安理工大学水利水电学院,西安710048

出　　处：《应用力学学报》2016年第5期826-831,936,共6页Chinese Journal of Applied Mechanics

摘　　要：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 components in shaft spillway, four cases of T_0=10.29 m, T_0=12.29 m, T_0=14.29 m and T_0=16.29 m, in the depth of the stilling wells are schemed, with the diameter of stilling well remains 7m; then the time-averaged pressure's distribution and variation and pulsating pressure parameters of circular inlet and stilling well and pressure slope part are studied. The result shows that, under the circumstance of free weir flow, the pressure value on the face of circle inlet is low, the negative pressure zone, 19 th measure point nearby, lies in the end of the weir surface curve; the bottom plane of stilling well has a high pressure value, the distribution of time-averaged pressure become more homogeneous with the increasing of well depth; there is no direct relationship between pressure variation and well depth increasing, the negative pressure zone of the pressure slope part lying in 1th measure point at the top plane has low value, and the value of the entire part is low; the time-averaged pressure value measured with piezometric tube is roughly equal to pulsating pressure measured; dominant frequency is lower than 1Hz, pulsating pressure in shaft spillway falls into low frequency band.

关 键 词：消能井 竖井溢洪道 时均压强 脉动压强 模型试验 

分 类 号：TV131[水利工程—水力学及河流动力学]