基于Hager对圆锥筒及圆柱体量水槽测流原理分析,推求出梯形渠道机翼形量水槽在自由出流时的流量理论计算公式,指出流量校正系数可由相对水头确定。选择6种收缩比进行了一系列室内模型试验,并根据试验数据建立了相对流量与相对水头的无量纲关系式。结果表明,相对流量与相对水头具有良好的相关关系,流量计算最大相对误差为±3.5%,该量水槽临界淹没度可达0.90,控制断面收缩比为0.372-0.585时可得到较好的量水效果。
Theoretical formula for discharge calculation of airfoil-shaped measuring flume in trapezoidal canal under free condition was proposed, based on the analysis on principle of circular cone and cylinder measuring flume which is presented by Hager. The coefficient of discharge correction is determined by relative head. A serial of indoor experiments about flume was carried out with 6 kinds of contraction ratios. Non-dimensional correlation between relative flow rate and relative head was developed according to experimental datum. The results show that there is a good relationship between relative flow rate and relative head. The maximum relative error of discharge calculation is less than + 3.5 %, and the maximum submergence limit is 0.90. A preferable water measuring performances is obtained when the contraction ratio ranges from 0. 372 to 0. 585.