矩形渠道Nystrom流线型量水槽试验研究

Experimental Study on Nystrom Streamline Measuring Flume in Rectangular Channel

为了探究流线型量水槽在矩形渠道的量水性能及适用性,通过Nystrom水滴型线构造不同收缩比流线型量水槽进行水力性能试验。通过分析槽前水深和喉口断面临界水深关系建立量水槽槽前水深流量公式,探讨了量水槽测流精度、上游弗劳德数、壅水高度和水头损失等测流特性。结果表明:量水槽槽前水深与流量相关度高,测流平均误差为1.74%,具有较高测流精度;上游弗劳德数、壅水高度、水头损失等水力要素均受量水槽收缩比与过流量影响。在试验条件下,上游弗劳德数均小于0.4,水流平缓,壅水高度与水头损失均较小,且均随量水槽收缩比的增大而减小,随渠道过流流量的增大而增大。

In order to explore the performance and applicability of the flow metering flume in rectangular channels,the hydraulic performance tests were carried out by constructing the flow metering flume with different shrinkage ratios with Nystrom drip line.By analyzing the water depth of upstream and the critical water depth of throat section,the flow measurement formula of measuring flume was established,and the measuring characteristics of measuring flume,such as measuring accuracy,upstream Froude number,backwater height and head loss were discussed.The results show that the water depth in front of the measuring tank has a high correlation with the discharge,and the average error of measuring flow is 1.74%,which has a high measuring accuracy.The hydraulic factors of upstream Froude number,backwater height and head loss are all affected by the shrinkage ratio of water tank and overflow.Under the test conditions,the upstream Froude number is smaller than 0.4,the water flow is gentle,the height of backwater and head loss are small,and they all decrease with the increase of the shrinkage ratio of the water tank,and increase with the increase of the channel overflow.