Experiment on hydraulic performance of portable triangular-throated flume for field ditch flow measurements
XUE Cheng, WANG Wene*, HU Xiaotao
Key Laboratory of Agricultural Soil and Water Engineering in Arid and Semiarid Areas, Ministry of Education, Northwest A & F University, Yangling, Shaanxi 712100, China
Abstract:This paper presents a new type of water measuring device, the portable triangle-throated measuring flume, which is suitable for small flow conditions and easily to be manufactured and installed. The hydraulic performance of a prototype flume is tested under free flow and submerged outflow conditions at 9 flow rates such as 0.90, 1.44, 1.88, 2.36, 2.84, 3.36, 3.92, 4.57 and 4.90 L/s. The flume is located in a U-shaped channel that is similar to a field irrigation ditch in cross-section, and the water levels at 13 control sections are measured. The hydraulic performance variables such as water surface line, Froude number, critical inundation degree, and measurement accuracy were analyzed. There is a good exponential relationship between the flow rate and the upstream water depth with a correlation coefficient of 0.999 5. A formula for flow rate in terms of water depth is obtained by curve fitting under free and inundation flow conditions. Compared with the experimental flow rates, the average and maximum errors are smaller than than 5%. The change rules of Froude number are analyzed, and the specific position for the critical water depth is determined, which is downstream the throat within a distance of 334-355 mm from the flume inlet. The critical submergence of the long triangular-throated flume is stable, ranged from 0.80 to 0.86. The suitable range of flow range is 0.90-5.00 L/s for a single flume.
薛城, 王文娥*, 胡笑涛. 沟灌简易量水槽水力性能探究[J]. 排灌机械工程学报, 2018, 36(11): 1104-1108.
XUE Cheng, WANG Wene*, HU Xiaotao. Experiment on hydraulic performance of portable triangular-throated flume for field ditch flow measurements. Journal of Drainage and Irrigation Machinery Engin, 2018, 36(11): 1104-1108.
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