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| DOI：10.13522/j.cnki.ggps.2019101 |
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| Comparative Analysis on Hydraulic Characteristics of Wing Pillar-shaped Measuring Flume |
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LIU Hongtao, NIU Yan, YU Mingzhou, HAN Yu
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1.College of Water and Environmental Engineering, Changchun Institute of Technology, Changchun 130012, China; 2. Water Conservancy and Civil Engineering College, Inner Mongolia Agricultural University, Hohhot 010018, China; 3. Laboratory of Applied Disaster Prevention in Water Conservation Engineering of Jilin Province, Changchun 130012, China; 4. College of Water Resources & Civil Engineering, China Agricultural University, Beijing 100083, China
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| Abstract: |
| 【Objective】In order to explore water performance of wing pillar-shaped measuring flume in free outflow and submerged outflow.【Method】The water levels of 13 flow measuring sections from the inlet to the outlet of the measuring flume under 10 kinds of flow were observed through experiments, and the hydraulic parameters such as water surface line, Froude number and flow measurement accuracy under free outflow and submerged outflow conditions could be analyzed and compared.【Result】Critical flow was formed between section 11 and section 12 under free outflow condition. And the minimum applicable flow rate of this type flume in U-shaped channel is 0.044 m3/s. The analysis results showed that there was a good correlation between flow rate and upstream water depth. Then the flow formula of the flume under free and submerged outflow conditions was obtained by fitting. The maximum error of free outflow is -2.54 % and that of submerged outflow is 6.50 %. The average error of both is less than 0.3 %, which meets the error requirements of current channel water measurement standards. The maximum submergence degree of the submerged outflow formula fitted in this paper is as high as 0.958, which has a wide application range. In addition, wing-column measuring flume in U-shaped channel has a large free outflow range, and the critical submergence degree can reach 0.890.【Conclusion】The critical flow section is located at 4 times the height of the wing of the measuring flume from the inlet. The wing pillar-shaped measuring flume can satisfy the requirement of flow measurement in small slope channels, and it solves the large error of the flow formula under the submerged outflow conditions. |
| Key words: wing pillar-shaped measuring flume; flow formula; submerged outflow; hydraulic performance; contrast test |
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