Shape design of right triangle measuring flume in U-shaped channel
The shape design for measuring flume is an important part of the application of measuring flume in irrigation areas.At present,there is no perfect standard to follow.In order to solve the problem of shape design in the practical application of right triangle measuring flume,the design criterion of measuring flume shape was proposed based on the limitation of submergence de-gree,backwater height and upstream Froude number.On the U-shaped channels of two types and three slopes,five right triangle measuring flumes were built with steel formwork for irrigation area test.A flow formula including channel bottom slope was estab-lished,and the empirical formulas of submergence threshold,backwater height and upstream Froude number were fitted.The re-sults showed that the accuracy of the flow formula with slope ratio was high,the average relative error was only1.88%,the maxi-mum relative error was5.56%,and the proportion of data with relative error within±5%was98%.The quantitative relation-ship between the submergence threshold,backwater height,upstream Froude number and the throat width of the measuring flume was obtained through three empirical formulas,which can be used for the shape design of the measuring flume.Based on the shape design criteria and empirical formulas,a right triangle measuring flume shape design method was established,in which the submer-gence degree was less than the corresponding submergence threshold under the maximum flow rate and the minimum flow rate,the backwater height was less than the super height of the channel bank top under the maximum flow rate,and the upstream Froude number was less than 0.5 under the minimum flow rate.The research results can be used for similar measuring flume shape de-sign.
right triangle measuring flumeU-shaped channelthroat widthsubmergence thresholdbackwater heightFroude number
国家科技期刊平台
NSTL
万方数据
维普
