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.
[1]COX A L, THORNTON C I, ABT S R. Supercritical flow measurement using a large parshall flume[J]. Journal of irrigation and drainage engineering, 2013,139(8): 655-662.[2]吴彩丽,黄斌,谢崇宝. 灌区量水技术与设备研究发展概况[J]. 中国水利, 2006(7):68. WU Caili, HUANG Bin, XIE Chongbao. Research and development of water measuring technology and equipment in irrigation district[J]. China water resources, 2006(7):68.(in Chinese)[3]刘小飞,费良军,孙景生,等. 垄植沟灌夏玉米棵间蒸发试验研究[J]. 排灌机械工程学报, 2016,34(4):332-338. LIU Xiaofei, FEI Liangjun, SUN Jingsheng, et al. Experiment on soil evaporation of summer maize in furrow irrigation[J]. Journal of drainage and irrigation machi-nery engineering, 2016,34(4):332-338.(in Chinese)[4]MANEKAR V L, POREY P D, INGLE R N. Discharge relation for cutthroat flume under free-flow condition[J]. Journal of irrigation and drainage engineering, 2007,133(5): 495-499.[5]HU Han, HUANG Jiesheng, QIAN Zhongdong, et al. Hydraulic analysis of parabolic flume for flow measurement[J]. Flow measurement and instrumentation, 2014,37:54-64.[6]金兆森, 程吉林. 介绍一种田间量水工具——移动式量水槽[J]. 江苏水利, 1991(2):58-63,70. JIN Zhaosen, CHENG Jilin. Introduce a field measuring water tool—movable flume[J]. Jiangsu water resources, 1991(2):58-63,70.(in Chinese)[7]吴迪,孟伟超,薄晓东,等. 不同地面灌溉方式对制种玉米产量与水分利用效率的影响[J]. 灌溉排水学报,2014,33(3/4):185-188. WU Di, MENG Weichao, BO Xiaodong, et al. Effect of different surface irrigation methods on yield and water use efficiency of maize for seed[J]. Journal of irrigation and drainage, 2014,33(3/4):185-188.(in Chinese)[8]肖苡辀, 王文娥, 胡笑涛. 田间便携式平底短喉道量水槽水力特性试验[J]. 农业工程学报, 2015, 31(10):99-106. XIAO Yizhou, WANG Wen′e, HU Xiaotao. Hydraulic performance experiment of portable short-throat flume with flat base in field[J]. Transactions of the CSAE, 2015,31(10):99-106.(in Chinese)
